# external variables

**URL:** <http://discourse.iapct.org/t/external-variables/13764>\
**Category:** CSG2017\
**Created:** [December 23, 2017, 1:53am UTC](http://discourse.iapct.org/t/external-variables/13764 "2017-12-23T01:53:30Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![bnhpct](http://discourse.iapct.org/user_avatar/discourse.iapct.org/bnhpct/32/34_2.png) [@bnhpct](http://discourse.iapct.org/u/bnhpct)\
**Post date:** [December 23, 2017, 1:53am UTC](http://discourse.iapct.org/t/external-variables/13764/1 "2017-12-23T01:53:30Z")

</div>

[From Bruce Nevin (2017.12.22.20:20 ET)]

I will try to put this very simply.

We can know that a variable is an external variable in two ways, by presumption and by coorboration.

We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.

We know this by corroboration when we perceive that another is controlling the variable that we are controlling.

We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.

> **···**
>
> > /Bruce

---

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**Author:** ![rsmarken](http://discourse.iapct.org/user_avatar/discourse.iapct.org/rsmarken/32/3553_2.png) [@rsmarken](http://discourse.iapct.org/u/rsmarken)\
**Post date:** [December 23, 2017, 10:55pm UTC](http://discourse.iapct.org/t/external-variables/13764/2 "2017-12-23T22:55:13Z")

</div>

[From Rick Marken (2017.12.23.1455)]

> **···**
>
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![bnhpct](http://discourse.iapct.org/user_avatar/discourse.iapct.org/bnhpct/32/34_2.png) [@bnhpct](http://discourse.iapct.org/u/bnhpct)\
**Post date:** [December 24, 2017, 3:15am UTC](http://discourse.iapct.org/t/external-variables/13764/3 "2017-12-24T03:15:25Z")

</div>

[From Bruce Nevin (2017.12.23.22:15 ET)]

Rick Marken (2017.12.23.1455) –

RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]

Yes. That is the presumption method.

> **···**
>
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> –

---

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**Author:** ![bnhpct](http://discourse.iapct.org/user_avatar/discourse.iapct.org/bnhpct/32/34_2.png) [@bnhpct](http://discourse.iapct.org/u/bnhpct)\
**Post date:** [December 24, 2017, 6:55pm UTC](http://discourse.iapct.org/t/external-variables/13764/4 "2017-12-24T18:55:22Z")

</div>

[From Bruce Nevin (2017.12.24.13:21 ET)]

> Rick Marken (2017.12.23.1455) –

> 

> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]

> 

> > Bruce Nevin (2017.12.23.22:15 ET) –

> >

> > BN: Yes. That is the presumption method.

And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable. During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.

By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.

Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.Â

The best of the season, and a new year coming.

> **···**
>
> On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > Rick Marken (2017.12.23.1455) –
> 
> > 
> 
> > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > 
> 
> > Yes. That is the presumption method.
> 
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> –

---

<div class="post-metadata">

**Author:** ![MartinT](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/m/ee7513/32.png) [@MartinT](http://discourse.iapct.org/u/MartinT)\
**Post date:** [December 25, 2017, 4:12am UTC](http://discourse.iapct.org/t/external-variables/13764/5 "2017-12-25T04:12:16Z")

</div>

[Martin Taylor 2017.12.24.10.03]

> [From Bruce Nevin (2017.12.23.22:15 ET)]

> ```
> Rick Marken
> 
> ```
> 
> (2017.12.23.1455) –

> 

> ```
> RM: I think we know that a
> 
> ```
> 
> variable is an external variable simply by examining our  
> world of experience; what we think of as the real world.  
> [etc. etc.]

> 

> ```
> Yes. That is the presumption
> 
> ```
> 
> method.

```
A sculptor is creating a bust of Napoleon by chipping away at a

```

block of marble. imagine watching him and see what we perceive. By " examining  
our world of experience; what we think of as the real world" we  
perceive that the block of marble is in the real world, I  
assume. But what do we mean by “the block of marble”? What about  
it is or is not in the real world? How about its colour? Is that  
in the real world? Is its colour described by its spectral  
reflectance? No, it is not.

```
          Here's a picture of the famous dress. Is it white

```

and gold or blue and black? Some people perceive one, some the  
other. This is not just an effects of having a picture of the  
dress. In a recent science show, the presenter wore the actual  
dress and asked people to judge under controlled lighting.  
Without changing the lighting, some said blue and black, while  
some said white and gold. What was in the real world?

```
   ![nkfdhedkbdkegejk.jpg|182x276](upload://9HgOvh10dDWUz3xVfEr3hMztAOx.jpeg)

Let's think more about the marble block. Is the spectral reflectance of the marble block in

```

the real world? We don’t perceive it directly, do we? We can  
perceive readings provided by instruments designed to measure  
it, and we perceive them to be in the real world. But do they  
tell the truth? Who knows? What  
properties allow us to say that it is a real block of anything, and  
if it is, that it consists of marble? I don’t know, but going to " our  
world of experience" I’m willing to assume that it is real and  
is marble if I see the sculptor chipping away at it and do not  
see or feel what I would expect to if I were in a virtual  
reality display.

```
          If the marble block is real, is the shape of the

```

bust of Napoleon? I can’t see it in the marble block when the  
sculptor receives the marble from the quarry. But maybe the  
sculptor can. It’s a reference shape, and all his chipping and  
polishing is action to reduce the error between the shape of the  
marble and the reference shape. The sculptor can see both, and  
the imaginary “I” watching the work progress can also see the  
current shape (and an ever-diminishing chink of marble). But “I”  
can’t see the shape of Napoleon until the sculptor indicates  
that the work is complete. Is that shape “out there” as,  
apparently, was the shape the sculptor was bringing toward the  
reference shape? The marble is, or at least we have assumed so.  
Are it’s height, width, and depth? If they are, how about the  
shape of Napoleon that is apparently a property of the finished  
bust?

> [From Bruce Nevin (2017.12.24.13:21 ET)]

> ```
> And the Test for the Controlled Variable is an especially
> 
> ```
> 
> rigorous form of corroboration–the other method of knowing that  
> a variable is an external variable. During the time that the  
> disturbance is being applied and resisted, if the investigator  
> has in fact identified the controlled variable, then both the  
> subject and the investigator are controlling the same variable  
> (at different reference values). The confirmation that it is the  
> same variable is an affirmation that the variable exists in a  
> public environment.

```
I don't think it is any corroboration at all. But it is evidence of

```

a kind, based on the assumption that the person you perceive to be  
performing the test really is.

```
Incidentally, I thought we cleared up the notion that the

```

experimenter performing the Test has a reference value for what the  
hypothesized variable’s value should be. The experimenter presumes  
that a hypothesised variable is being controlled and constructs a  
form of disturbance that would ideally disturb that variable and  
that alone. But this disturbance is unrelated to the variable’s  
value at any moment, and is not varied in coordination with changes  
of the variable’s value.

```
More importantly for the issue in question, I said "ideally" above.

```

But that disturbance will disturb not only the hypothesised variable  
but also any variable correlated with it. If the subject is  
controlling X+Y and the experimenter creates a disturbance that  
influences 2X+Y, the experimenter will observe that 2X+Y is being  
controlled, not well, perhaps, but controlled nevertheless. Which  
one exists in the real world according to this rigorous form of  
corroboration?

> 

> …

> 

> ```
> Extending the question, Bill wrote a couple of times on
> 
> ```
> 
> CSGnet about the problem of solipsism. We know it is false, but  
> we can’t prove it. He said “if anyone can find a way out of  
> this, I’d like to know”, or words to that effect. The way out,  
> of course, is each other.

```
Really? How do I know you aren't a figment of my imagination, along

```

with all the conflicts and collaborations? How do I know that you  
aren’t a consequence of a myriad elves manipulating my peripheral  
sensors to create the impression that you are real? I don’t think  
you can solve Bill’s problem so easily. The interesting question is  
one that assumes that at least some of what we consciously perceive  
(emphasizing “consciously”) corresponds reasonably well to some real  
external variable. With that assumption, the question is: “Of what  
we perceive to be “out there”, what actually is, and what is not?”

```
A quite separate question is based on an assumption that PCT is

```

basically correct. This question dismisses conscious perception and  
asks: "Of the perceptual signals in a perceptual control hierarchy,  
how well does any specific one correspond to some variable that is  
really “out there”. That’s a harder question to answer, but I think  
“The Test” allows us to converge on an answer in some circumstances.  
Going back to the problem of X+Y versus 2X+Y, if the subject really  
is controlling a variable X+Y that depends only on X and Y, then the  
apparent control of X+Y will be better than control of aX+bY where  
a≠b. This being the case, many applications of the test with  
disturbances tuned to all values of a and b for a given value of a+b  
will eventually converge on a=b as being correct. But there are  
other dimensions along which the hypothesis might vary, such as the  
recent history of X and of Y, which probably matters, given that our  
“apparently real” peripheral sensors report contrasts rather than  
steady values.

```
In other words, you can never be sure exactly what perception in the

```

hierarchy is being controlled, even if it were possible to segregate  
one from others to which it is related in levels above and below.  
It’s possible to do this when the question is which member of a  
category is being controlled, as in Rick’s demos, since the set of  
possibilities is finite (and manageably small). But what is really  
“out there” even in that case? And how do the conscious perceptions  
of apparently real things relate to what goes on either in the  
brain, or in the functional approximation represented by the  
abstraction we call PCT?

```
I think the only way to discover what is real and what is not

```

(assuming that at least some things are) depends on the possibility  
of controlling a perception of it oneself, and that applies only to  
conscious perception. For perceptual signals in the hierarchy, the  
bet is based on evolution and reorganization. If controlling what  
you perceive has had no influence influence on intrinsic variables  
and continues to have none, you are likely to lose the ability to  
perceive that variable, and it probably wasn’t real in the first  
place.

> ```
> Conflict, collaboration, and other forms of collective
> 
> ```
> 
> control affirm not only the existence of external variables, but  
> also the existence of each other. Is that proof? is it proof  
> (that is, secure) against hallucination? I think it’s all we’ve  
> got. Each other. Let’s make the best of it, friends.

> 

> The best of the season, and a new year coming.

```
And the same to you, whom I believe to exist in the real world, and

```

to all CSGnet readers, who have equal claim to existence. Belief is  
all I have, no matter how much I conflict, collaborate, or join with  
you in collective control.

```
Martin

```

---

<div class="post-metadata">

**Author:** ![\_Boris\_Hartman](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/e8c25b/32.png) [@\_Boris\_Hartman](http://discourse.iapct.org/u/_Boris_Hartman)\
**Post date:** [December 26, 2017, 5:23pm UTC](http://discourse.iapct.org/t/external-variables/13764/6 "2017-12-26T17:23:31Z")

</div>

Bruce and Rick let’s cut the »bullshitt«. Do something usefull for PCT.

Do you agree with, well you know what.

Definitions of PCT control loop :

Bill P (B:CP):

1. 

```
 CONTROL : Achievement and maintenance of a preselected state in the controlling system, through actions on the environment that also cancel the effects of disturbances.

```

Bill P (B:CP):

1. 

```
 OUTPUT FUNCTION : The portion of a system that converts the magnitude or state of a signal inside the system into a corresponding set of effects on the immediate environment of the system

```

Bill P (LCS III):… **the output function** shown in it’ss own box represents the means this system has for causing changes in it’s environment.

Bill P (LCS III):

1. 

```
  FEED-BACK FUNCTION : The box represents the set of physical laws, properties, arrangements, linkages, by which the action of this system feeds-back to affect its own input, the controlled variable. That's what feed-back means : it's an effect of a system's output on it's own input.

```

Bill P (B:CP) :

1. 

```
 INPUT FUNCTION : The portion of a system that receives signals or stimuli from outside the system, and generates a perceptual signal that is some function of the received signals or stimuli.

```

Bill P (B:CP) :

1. 

```
 COMPARATOR : The portion of control system that computes the magnitude and direction of mismatch between perceptual and reference signal.

```

Bill P (B:CP)

1. 

```
  : ERROR : The discrepancy between a perceptual signal and a reference signal, which drives a control system’s output function. The discrepancy between a controlled quantity and it’s present reference level, which causes observable behavior.

```

Bill P (B:CP) :

1. 

```
 ERROR SIGNAL : A signal indicating the magnitude and direction of error.

```

 ![image001185.jpg](http://discourse.iapct.org/uploads/default/original/1X/44a2f59a2b0e372e628fe045855d7d8cc3435e60.jpeg)

> **···**
>
> **From:** Richard Marken [[mailto:rsmarken@gmail.com](mailto:rsmarken@gmail.com)]  
> **Sent:** Saturday, December 23, 2017 11:55 PM  
> **To:** csgnet@lists.illinois.edu  
> **Subject:** Re: external variables
> 
> [From Rick Marken (2017.12.23.1455)]
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables.
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.
> 
> Best
> 
> Rick
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > > /Bruce
> 
> –
> 
> Richard S. Marken
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> –Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![Joh\_Orengo](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@Joh\_Orengo](http://discourse.iapct.org/u/Joh_Orengo)\
**Post date:** [December 26, 2017, 9:22pm UTC](http://discourse.iapct.org/t/external-variables/13764/7 "2017-12-26T21:22:27Z")

</div>

Martin wrote, “Belief is  
all I have, no matter how much I conflict, collaborate, or join with  
you in collective control.”

This.

Joh

![nkfdhedkbdkegejk.jpg](http://discourse.iapct.org/uploads/default/original/1X/43f7c2a53f97f1ce4fcfe8bb35098ba6d6c994d5.jpeg)

---

<div class="post-metadata">

**Author:** ![rsmarken](http://discourse.iapct.org/user_avatar/discourse.iapct.org/rsmarken/32/3553_2.png) [@rsmarken](http://discourse.iapct.org/u/rsmarken)\
**Post date:** [December 27, 2017, 12:25am UTC](http://discourse.iapct.org/t/external-variables/13764/8 "2017-12-27T00:25:03Z")

</div>

[From Rick Marken (2017.12.26.1620)]

> **···**
>
> > Bruce Nevin (2017.12.24.13:21 ET)
> 
> > >
> 
> > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]
> 
> > > >
> 
> > > > BN: Yes. That is the presumption method.
> 
> > 
> 
> > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable.
> 
> RM: Again, the phrase “external variable” as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. “External variable” does not refer to external reality – it refers to perceptual variables that we take for external reality.Â
> 
> RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment --Â a reality – in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.Â
> 
> RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as _functions_ of the variables in the physical/chemical models of the environment.Â
> 
> RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the “environment” in PCT is the physical model of external reality that comes from the models of physics and chemistry.Â
> 
> RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is _assumed_ to exist in PCT and it exists in PCT as the models of physical sciences.Â
> 
> BestÂ
> 
> Rick
> 
> Â
> 
> > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> 
> > 
> 
> > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> 
> > 
> 
> > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.Â
> 
> > 
> 
> > The best of the season, and a new year coming.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> > 
> 
> > 
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > Rick Marken (2017.12.23.1455) –
> 
> > 
> 
> > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > 
> 
> > Yes. That is the presumption method.
> 
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> –

---

<div class="post-metadata">

**Author:** ![Joh\_Orengo](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@Joh\_Orengo](http://discourse.iapct.org/u/Joh_Orengo)\
**Post date:** [December 27, 2017, 6:46am UTC](http://discourse.iapct.org/t/external-variables/13764/9 "2017-12-27T06:46:20Z")

</div>

Rick,

If “PCT is based on an epistemology that assumes that we have no direct access to the environment” then it sound like it matches indirect perception/indirect realism, which states that “the world we see around us in  
visual consciousness…is merely  
a perceptual replica of [the real world (“out there”)] in an internal representation”. Would you say that that is accurate?

(I quoted this from Steven Lehar “The Epistemology of Conscious Experience” at

[http://cns-alumni.bu.edu/~slehar/epist/epist.html](http://cns-alumni.bu.edu/~slehar/epist/epist.html))

Joh

> **···**
>
> Sent with [ProtonMail](https://protonmail.com) Secure Email.
> 
> > -------- Original Message --------
> 
> > Subject: Re: external variables
> 
> > Local Time: December 27, 2017 2:25 AM
> 
> > UTC Time: December 27, 2017 12:25 AM
> 
> > From: [rsmarken@gmail.com](mailto:rsmarken@gmail.com)
> 
> > To: csgnet@lists.illinois.edu
> 
> > 
> 
> > [From Rick Marken (2017.12.26.1620)]
> 
> > 
> 
> > > Bruce Nevin (2017.12.24.13:21 ET)
> 
> > > >
> 
> > > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]
> 
> > > > >
> 
> > > > > BN: Yes. That is the presumption method.
> 
> > >
> 
> > > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable.
> 
> > 
> 
> > RM: Again, the phrase “external variable” as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. “External variable” does not refer to external reality – it refers to perceptual variables that we take for external reality.
> 
> > 
> 
> > RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment – a reality – in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.
> 
> > 
> 
> > RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as _functions_ of the variables in the physical/chemical models of the environment.
> 
> > 
> 
> > RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the “environment” in PCT is the physical model of external reality that comes from the models of physics and chemistry.
> 
> > 
> 
> > RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is _assumed_ to exist in PCT and it exists in PCT as the models of physical sciences.
> 
> > 
> 
> > Best
> 
> > 
> 
> > Rick
> 
> > 
> 
> > > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> 
> > >
> 
> > > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> 
> > >
> 
> > > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.
> 
> > >
> 
> > > The best of the season, and a new year coming.
> 
> > >
> 
> > > > /Bruce
> 
> > >
> 
> > >
> 
> > >
> 
> > >
> 
> > >
> 
> > > On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > > > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > > >
> 
> > > > Rick Marken (2017.12.23.1455) –
> 
> > > >
> 
> > > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > > >
> 
> > > > Yes. That is the presumption method.
> 
> > > >
> 
> > > > On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > > > > [From Rick Marken (2017.12.23.1455)]
> 
> > > > >
> 
> > > > > > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > > > > >
> 
> > > > > > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> > > > >
> 
> > > > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> > > > >
> 
> > > > > RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables.
> 
> > > > >
> 
> > > > > RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.
> 
> > > > >
> 
> > > > > RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.
> 
> > > > >
> 
> > > > > Best
> 
> > > > >
> 
> > > > > Rick
> 
> > > > >
> 
> > > > >
> 
> > > > > >
> 
> > > > > > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > > > > >
> 
> > > > > > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.
> 
> > > > > >
> 
> > > > > > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > > > > >
> 
> > > > > > > /Bruce
> 
> > > > >
> 
> > > > >
> 
> > > > >
> 
> > > > > –
> 
> > > > > Richard S. Marken
> 
> > > > >
> 
> > > > > "Perfection is achieved not when you have nothing more to add, but when you
> 
> > > > > have nothing left to take away.�
> 
> > > > > ```
> > > > > --Antoine de Saint-Exupery
> > > > > 
> > > > > ```
> 
> > > > >
> 
> > > >
> 
> > >
> 
> > 
> 
> > 
> 
> > 
> 
> > –
> 
> > Richard S. Marken
> 
> > 
> 
> > "Perfection is achieved not when you have nothing more to add, but when you
> 
> > have nothing left to take away.�
> 
> > ```
> > --Antoine de Saint-Exupery
> > 
> > ```
> 
> >

---

<div class="post-metadata">

**Author:** ![rsmarken](http://discourse.iapct.org/user_avatar/discourse.iapct.org/rsmarken/32/3553_2.png) [@rsmarken](http://discourse.iapct.org/u/rsmarken)\
**Post date:** [December 27, 2017, 9:02pm UTC](http://discourse.iapct.org/t/external-variables/13764/10 "2017-12-27T21:02:57Z")

</div>

[From Rick Marken (2017.12.27.1300)]

> **···**
>
> On Tue, Dec 26, 2017 at 10:46 PM, Joh Orengo [joh.orengo@protonmail.com](mailto:joh.orengo@protonmail.com) wrote:
> 
> > JO: Rick, If “PCT is based on an epistemology that assumes that we have no direct access to the environment” then it sound like it matches indirect perception/indirect realism, which states that “the world we see around us in  
> > visual consciousness…is merely  
> > a perceptual replica of [the real world (“out there”)] in an internal representation”. Would you say that that is accurate?
> 
> RM: I would say that PCT does say that perception of external reality is _indirect_ in the sense that whatever is “out there” must go through the interface of our senses before it exists as perceptions; indeed, I can’t imagine any theory of perception that is not indirect in this sense. But the PCT model of perception is better called “constructivism” than “realism”. In PCT, perception is not a replica of the real world out there; rather, perception is a function of the variables that physical science tells us makes up the “real world” out there – the environment in which we exist. These functions “construct” our perceptions from the raw material that is the sensed effects of variables in the physical world. They are not a replica of reality since the “reality” that is assumed to exist on the other side of our senses is the reality of physical science. We don’t experience that reality; we experience perceptions that are functions of the sensory effects of that reality. Â
> 
> BestÂ
> 
> Rick
> 
> > (I quoted this from Steven Lehar “The Epistemology of Conscious Experience” at
> 
> > [http://cns-alumni.bu.edu/~slehar/epist/epist.html](http://cns-alumni.bu.edu/~slehar/epist/epist.html))
> 
> > 
> 
> > Joh
> 
> > 
> 
> > 
> 
> > Sent with [ProtonMail](https://protonmail.com) Secure Email.
> 
> > 
> 
> > > -------- Original Message --------
> 
> > > Subject: Re: external variables
> 
> > > Local Time: December 27, 2017 2:25 AM
> 
> > > UTC Time: December 27, 2017 12:25 AM
> 
> > > From: [rsmarken@gmail.com](mailto:rsmarken@gmail.com)
> 
> > > To: csgnet@lists.illinois.edu
> 
> > >
> 
> > > [From Rick Marken (2017.12.26.1620)]
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> > Bruce Nevin (2017.12.24.13:21 ET)
> 
> > >
> 
> > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]
> 
> > > >
> 
> > > > BN: Yes. That is the presumption method.
> 
> > 
> 
> > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable.
> 
> RM: Again, the phrase “external variable” as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. “External variable” does not refer to external reality – it refers to perceptual variables that we take for external reality.Â
> 
> RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment --Â a reality – in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.Â
> 
> RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as _functions_ of the variables in the physical/chemical models of the environment.Â
> 
> RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the “environment” in PCT is the physical model of external reality that comes from the models of physics and chemistry.Â
> 
> RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is _assumed_ to exist in PCT and it exists in PCT as the models of physical sciences.Â
> 
> BestÂ
> 
> Rick
> 
> Â
> 
> > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> 
> > 
> 
> > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> 
> > 
> 
> > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.Â
> 
> > 
> 
> > The best of the season, and a new year coming.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> > 
> 
> > 
> 
> > 
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > 
> 
> > Rick Marken (2017.12.23.1455) –
> 
> > 
> 
> > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > 
> 
> > Yes. That is the presumption method.
> 
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > 
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![Joh\_Orengo](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@Joh\_Orengo](http://discourse.iapct.org/u/Joh_Orengo)\
**Post date:** [December 27, 2017, 9:26pm UTC](http://discourse.iapct.org/t/external-variables/13764/11 "2017-12-27T21:26:21Z")

</div>

> Subject: Re: external variables  
> Local Time: December 27, 2017 11:02 PM  
> UTC Time: December 27, 2017 9:02 PM  
> From: rsmarken@gmail.com  
> To: csgnet@lists.illinois.edu
> 
> [From Rick Marken (2017.12.27.1300)]
> 
> > JO: Rick, If "PCT is based on an epistemology that assumes that we have no direct access to the environment" then it sound like it matches indirect perception/indirect realism, which states that "the world we see around us in visual consciousness...is merely a perceptual replica of [the real world ("out there")] in an internal representation". Would you say that that is accurate?
> 
> RM: I would say that PCT does say that perception of external reality is indirect in the sense that whatever is "out there" must go through the interface of our senses before it exists as perceptions; indeed, I can't imagine any theory of perception that is not indirect in this sense. But the PCT model of perception is better called "constructivism" than "realism". In PCT, perception is not a replica of the real world out there; rather, perception is a function of the variables that physical science tells us makes up the "real world" out there -- the environment in which we exist. These functions "construct" our perceptions from the raw material that is the sensed effects of variables in the physical world. They are not a replica of reality since the "reality" that is assumed to exist on the other side of our senses is the reality of physical science. We don't experience that reality; we experience perceptions that are functions of the sensory effects of that reality.

Thank you for the response, Rick. Yes, a 'constructivist' approach makes more sense than a 'realist' one from the PCT perspective.

Joh

> **···**
>
> Sent with \<[https://protonmail.com](https://protonmail.com)\>ProtonMail Secure Email.
> 
> > -------- Original Message --------  
> > On Tue, Dec 26, 2017 at 10:46 PM, Joh Orengo \<\<mailto:joh.orengo@protonmail.com\>joh.orengo@protonmail.com\> wrote:
> > 
> > Best
> > 
> > Rick
> > 
> > > (I quoted this from Steven Lehar "The Epistemology of Conscious Experience" at  
> > > \<[http://cns-alumni.bu.edu/~slehar/epist/epist.html&gt;&gt;&gt](http://cns-alumni.bu.edu/~slehar/epist/epist.html&gt;&gt;&gt); [http://cns-alumni.bu.edu/~slehar/epist/epist.html\](http://cns-alumni.bu.edu/~slehar/epist/epist.html%5C))
> > > 
> > > Joh
> > > 
> > > Sent with \<[https://protonmail.com](https://protonmail.com)\>ProtonMail Secure Email.
> > > 
> > > > -------- Original Message --------  
> > > > Subject: Re: external variables  
> > > > Local Time: December 27, 2017 2:25 AM  
> > > > UTC Time: December 27, 2017 12:25 AM  
> > > > From: \<mailto:rsmarken@gmail.com\>rsmarken@gmail.com  
> > > > To: \<mailto:csgnet@lists.illinois.edu\>csgnet@lists.illinois.edu
> > > > 
> > > > [From Rick Marken (2017.12.26.1620)]
> > > > 
> > > > > Bruce Nevin (2017.12.24.13:21 ET)
> > > > > 
> > > > > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [...]
> > > > > > 
> > > > > > > BN: Yes. That is the presumption method.
> > > > > 
> > > > > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration--the other method of knowing that a variable is an external variable.
> > > > 
> > > > RM: Again, the phrase "external variable" as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. "External variable" does not refer to external reality -- it refers to perceptual variables that we take for external reality.
> > > > 
> > > > RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment -- a reality -- in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.
> > > > 
> > > > RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as functions of the variables in the physical/chemical models of the environment.
> > > > 
> > > > RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the "environment" in PCT is the physical model of external reality that comes from the models of physics and chemistry.
> > > > 
> > > > RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is assumed to exist in PCT and it exists in PCT as the models of physical sciences.
> > > > 
> > > > Best
> > > > 
> > > > Rick
> > > > 
> > > > > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> > > > > 
> > > > > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> > > > > 
> > > > > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can't prove it. He said "if anyone can find a way out of this, I'd like to know", or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it's all we've got. Each other. Let's make the best of it, friends.
> > > > > 
> > > > > The best of the season, and a new year coming.
> > > > > 
> > > > > > /Bruce
> > > > > 
> > > > > On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin \<\<mailto:bnhpct@gmail.com\>bnhpct@gmail.com\> wrote:
> > > > > 
> > > > > > [From Bruce Nevin (2017.12.23.22:15 ET)]
> > > > > > 
> > > > > > Rick Marken (2017.12.23.1455) --
> > > > > > 
> > > > > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> > > > > > 
> > > > > > Yes. That is the presumption method.
> > > > > > 
> > > > > > On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken \<\<mailto:rsmarken@gmail.com\>rsmarken@gmail.com\> wrote:
> > > > > > 
> > > > > > > [From Rick Marken (2017.12.23.1455)]
> > > > > > > 
> > > > > > > > Bruce Nevin (2017.12.22.20:20 ET)
> > > > > > > > 
> > > > > > > > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> > > > > > > 
> > > > > > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like "behavior", "external variable" is not a technical term. Bill used it in his letter to Phil because it's a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT ("it's all perception"), but are experienced as features of the world "out there". For example, in the "What is Size" demo the area of the rectangle looks like a variable aspect of the the world that is "out there", external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an "external variable" -- since it is experienced as such -- and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since "it's all perception").
> > > > > > > 
> > > > > > > RM: What is important about the term "external variable" as a description of our perceptions of the world is the "variable" part. In PCT we recognize that what are controlled are variables -- the variables we experience as external reality. So the external world that I am experiencing and controlling -- the keys I'm pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables.
> > > > > > > 
> > > > > > > RM: These "external variables" are presumed to be of different classes -- different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass ".. from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves -- from the world of "physical reality" to the world of "subjective reality". So the term "external variable" is really most appropriate for the classes of perception we see as "out there" -- the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like "physical reality". Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called "internal variables" or "cognitive variables". But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.
> > > > > > > 
> > > > > > > RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a hypothesis that Bill came up by examining is own perceptual experience -- and he presents evidence for each of the proposed level in B:CP. But this hypothesis -- that behavior is the control of different classes of perceptual variable -- should be tested; this is what Bill thought should be the main goal of PCT - based research.
> > > > > > > 
> > > > > > > Best
> > > > > > > 
> > > > > > > Rick
> > > > > > > 
> > > > > > > > We know this by presumption all the time, by routinely experiencing our perceptions as "out there" in the environment. Success at adequately controlling our perceptions is generally verification enough.
> > > > > > > > 
> > > > > > > > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.
> > > > > > > > 
> > > > > > > > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> > > > > > > > 
> > > > > > > > > /Bruce
> > > > > > > 
> > > > > > > --  
> > > > > > > Richard S. Marken
> > > > > > > 
> > > > > > > "Perfection is achieved not when you have nothing more to add, but when you  
> > > > > > > have nothing left to take away.�  
> > > > > > > --Antoine de Saint-Exupery
> > > > 
> > > > --  
> > > > Richard S. Marken
> > > > 
> > > > "Perfection is achieved not when you have nothing more to add, but when you  
> > > > have nothing left to take away.�  
> > > > --Antoine de Saint-Exupery
> > 
> > --  
> > Richard S. Marken
> > 
> > "Perfection is achieved not when you have nothing more to add, but when you  
> > have nothing left to take away.�  
> > --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![bnhpct](http://discourse.iapct.org/user_avatar/discourse.iapct.org/bnhpct/32/34_2.png) [@bnhpct](http://discourse.iapct.org/u/bnhpct)\
**Post date:** [December 28, 2017, 1:41am UTC](http://discourse.iapct.org/t/external-variables/13764/12 "2017-12-28T01:41:31Z")

</div>

[From Bruce Nevin (2017.12.27.19:44 ET)]

> RM:Â Â the “reality” that is assumed to exist on the other side of our senses is the reality of physical science.Â

IMO, the physical sciences are necessarily constructivist as well, though they are commonly taken as a basis for one or another flavor of realism. As I said about corroboration, it’s the best we’ve got (so far).

My friend Tom Ryckman, who has researched and written extensively about Einstein, offered this summary statement in a recent [interview](https://www.routledge.com/philosophy/posts/12211?utm_source=Routledge&utm_medium=cms&utm_campaign=170606695):

> Einstein demonstrates that it is possible to be a “realist� about science without adopting the metaphysical presuppositions of what is today called “scientific realism�. In particular, Einstein balanced the aspirational or motivational realist attitude of many working scientists with the clear recognition that realism remains a metaphysical hypothesis, not demonstrable by empirical evidence.

This is fully compatible with the attitude we have been deriving from PCT, and seems to me to make constructivism necessary.

A bit of background: Tom was a student of Zellig Harris (his 1986 dissertation is [here](http://zelligharris.org/Ryckman1991.pdf)). Zellig’s theory of language and information is constructivist and naturalist. His first wife Bruria Kaufmann was Einstein’s mathematical assistant at Princeton, and the three had a friendship. Tom has written two books, _The Reign of Relativity: Philosophy in Physics 1915-1925_ (Oxford) and most recently _Einstein_ (in the Routledge Philosophers series), and he was a co-author with Zellig and others of _The form of information in science_.

> **···**
>
> On Wed, Dec 27, 2017 at 4:02 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.27.1300)]
> 
> On Tue, Dec 26, 2017 at 10:46 PM, Joh Orengo [joh.orengo@protonmail.com](mailto:joh.orengo@protonmail.com) wrote:
> 
> > JO: Rick, If “PCT is based on an epistemology that assumes that we have no direct access to the environment” then it sound like it matches indirect perception/indirect realism, which states that “the world we see around us in  
> > visual consciousness…is merely  
> > a perceptual replica of [the real world (“out there”)] in an internal representation”. Would you say that that is accurate?
> 
> RM: I would say that PCT does say that perception of external reality is _indirect_ in the sense that whatever is “out there” must go through the interface of our senses before it exists as perceptions; indeed, I can’t imagine any theory of perception that is not indirect in this sense. But the PCT model of perception is better called “constructivism” than “realism”. In PCT, perception is not a replica of the real world out there; rather, perception is a function of the variables that physical science tells us makes up the “real world” out there – the environment in which we exist. These functions “construct” our perceptions from the raw material that is the sensed effects of variables in the physical world. They are not a replica of reality since the “reality” that is assumed to exist on the other side of our senses is the reality of physical science. We don’t experience that reality; we experience perceptions that are functions of the sensory effects of that reality. Â
> 
> BestÂ
> 
> Rick
> 
> > (I quoted this from Steven Lehar “The Epistemology of Conscious Experience” at
> 
> > [http://cns-alumni.bu.edu/~slehar/epist/epist.html](http://cns-alumni.bu.edu/~slehar/epist/epist.html))
> 
> > 
> 
> > Joh
> 
> > 
> 
> > 
> 
> > Sent with [ProtonMail](https://protonmail.com) Secure Email.
> 
> > 
> 
> > > -------- Original Message --------
> 
> > > Subject: Re: external variables
> 
> > > Local Time: December 27, 2017 2:25 AM
> 
> > > UTC Time: December 27, 2017 12:25 AM
> 
> > > From: [rsmarken@gmail.com](mailto:rsmarken@gmail.com)
> 
> > > To: csgnet@lists.illinois.edu
> 
> > >
> 
> > > [From Rick Marken (2017.12.26.1620)]
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> > Bruce Nevin (2017.12.24.13:21 ET)
> 
> > >
> 
> > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]
> 
> > > >
> 
> > > > BN: Yes. That is the presumption method.
> 
> > 
> 
> > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable.
> 
> RM: Again, the phrase “external variable” as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. “External variable” does not refer to external reality – it refers to perceptual variables that we take for external reality.Â
> 
> RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment --Â a reality – in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.Â
> 
> RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as _functions_ of the variables in the physical/chemical models of the environment.Â
> 
> RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the “environment” in PCT is the physical model of external reality that comes from the models of physics and chemistry.Â
> 
> RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is _assumed_ to exist in PCT and it exists in PCT as the models of physical sciences.Â
> 
> BestÂ
> 
> Rick
> 
> Â
> 
> > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> 
> > 
> 
> > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> 
> > 
> 
> > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.Â
> 
> > 
> 
> > The best of the season, and a new year coming.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> > 
> 
> > 
> 
> > 
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > 
> 
> > Rick Marken (2017.12.23.1455) –
> 
> > 
> 
> > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > 
> 
> > Yes. That is the presumption method.
> 
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > 
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![Joh\_Orengo](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@Joh\_Orengo](http://discourse.iapct.org/u/Joh_Orengo)\
**Post date:** [December 28, 2017, 6:21am UTC](http://discourse.iapct.org/t/external-variables/13764/13 "2017-12-28T06:21:38Z")

</div>

> Subject: Re: external variables  
> Local Time: December 28, 2017 3:41 AM  
> UTC Time: December 28, 2017 1:41 AM  
> From: bnhpct@gmail.com  
> To: CSG \<csgnet@lists.illinois.edu\>
> 
> [From Bruce Nevin (2017.12.27.19:44 ET)]
> 
> > RM: the "reality" that is assumed to exist on the other side of o ur senses is the reality of physical science.
> 
> IMO, the physical sciences are necessarily constructivist as well, though they are commonly taken as a basis for one or another flavor of realism...
> 
> This is fully compatible with the attitude we have been deriving from PCT, and seems to me to make constructivism necessary.
> 
> /Bruce

I agree. Models of reality on top of models of reality on top of models...

Joh

> **···**
>
> Sent with \<[https://protonmail.com](https://protonmail.com)\>ProtonMail Secure Email.
> 
> > -------- Original Message --------

---

<div class="post-metadata">

**Author:** ![rsmarken](http://discourse.iapct.org/user_avatar/discourse.iapct.org/rsmarken/32/3553_2.png) [@rsmarken](http://discourse.iapct.org/u/rsmarken)\
**Post date:** [December 28, 2017, 11:05pm UTC](http://discourse.iapct.org/t/external-variables/13764/14 "2017-12-28T23:05:39Z")

</div>

[From Rick Marken (2017.12.28.1500)]

> **···**
>
> > Bruce Nevin (2017.12.27.19:44 ET)]
> 
> > > RM:Â Â the “reality” that is assumed to exist on the other side of our senses is the reality of physical science.Â
> 
> > 
> 
> > BN: IMO, the physical sciences are necessarily constructivist as well, though they are commonly taken as a basis for one or another flavor of realism. As I said about corroboration, it’s the best we’ve got (so far).
> 
> RM: In what way is science “constructivist”? I think of science as disciplined imagination; the “imagination” being the theories that are invented to explain what we experience; the “discipline” being the testing of these theories to see if what they predict actually happens. Corroboration is nice – having more than one person agree that the perceived result of an experiment is what was predicted by the theory – but not essential to science. A good scientist, like your friend Einstein and my friends Powers, knows that theories, even when the predict perfectly, are not reality; they are simply our current best approximations to that reality.
> 
> RM: In PCT, we should keep in mind that the physical theories that we use as our models of the environment are just that; models, not reality. Similarly, we should keep in mind that the hierarchical control theory that is used as a model of organisms, is also a model, not reality. It seems to me that people on CSGNet are much better at rejecting the “realism” of the physical model of the than they are at rejecting the realism of the hierarchical control model of the behavior of the organisms that are part of that environment.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > My friend Tom Ryckman, who has researched and written extensively about Einstein, offered this summary statement in a recent [interview](https://www.routledge.com/philosophy/posts/12211?utm_source=Routledge&utm_medium=cms&utm_campaign=170606695):
> 
> > 
> 
> > > Einstein demonstrates that it is possible to be a “realist� about science without adopting the metaphysical presuppositions of what is today called “scientific realism�. In particular, Einstein balanced the aspirational or motivational realist attitude of many working scientists with the clear recognition that realism remains a metaphysical hypothesis, not demonstrable by empirical evidence.
> 
> > 
> 
> > This is fully compatible with the attitude we have been deriving from PCT, and seems to me to make constructivism necessary.
> 
> > 
> 
> > A bit of background: Tom was a student of Zellig Harris (his 1986 dissertation is [here](http://zelligharris.org/Ryckman1991.pdf)). Zellig’s theory of language and information is constructivist and naturalist. His first wife Bruria Kaufmann was Einstein’s mathematical assistant at Princeton, and the three had a friendship. Tom has written two books, _The Reign of Relativity: Philosophy in Physics 1915-1925_ (Oxford) and most recently _Einstein_ (in the Routledge Philosophers series), and he was a co-author with Zellig and others of _The form of information in science_.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Wed, Dec 27, 2017 at 4:02 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.27.1300)]
> 
> On Tue, Dec 26, 2017 at 10:46 PM, Joh Orengo [joh.orengo@protonmail.com](mailto:joh.orengo@protonmail.com) wrote:
> 
> > JO: Rick, If “PCT is based on an epistemology that assumes that we have no direct access to the environment” then it sound like it matches indirect perception/indirect realism, which states that “the world we see around us in  
> > visual consciousness…is merely  
> > a perceptual replica of [the real world (“out there”)] in an internal representation”. Would you say that that is accurate?
> 
> RM: I would say that PCT does say that perception of external reality is _indirect_ in the sense that whatever is “out there” must go through the interface of our senses before it exists as perceptions; indeed, I can’t imagine any theory of perception that is not indirect in this sense. But the PCT model of perception is better called “constructivism” than “realism”. In PCT, perception is not a replica of the real world out there; rather, perception is a function of the variables that physical science tells us makes up the “real world” out there – the environment in which we exist. These functions “construct” our perceptions from the raw material that is the sensed effects of variables in the physical world. They are not a replica of reality since the “reality” that is assumed to exist on the other side of our senses is the reality of physical science. We don’t experience that reality; we experience perceptions that are functions of the sensory effects of that reality. Â
> 
> BestÂ
> 
> Rick
> 
> > (I quoted this from Steven Lehar “The Epistemology of Conscious Experience” at
> 
> > [http://cns-alumni.bu.edu/~slehar/epist/epist.html](http://cns-alumni.bu.edu/~slehar/epist/epist.html))
> 
> > 
> 
> > Joh
> 
> > 
> 
> > 
> 
> > Sent with [ProtonMail](https://protonmail.com) Secure Email.
> 
> > 
> 
> > > -------- Original Message --------
> 
> > > Subject: Re: external variables
> 
> > > Local Time: December 27, 2017 2:25 AM
> 
> > > UTC Time: December 27, 2017 12:25 AM
> 
> > > From: [rsmarken@gmail.com](mailto:rsmarken@gmail.com)
> 
> > > To: csgnet@lists.illinois.edu
> 
> > >
> 
> > > [From Rick Marken (2017.12.26.1620)]
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> > Bruce Nevin (2017.12.24.13:21 ET)
> 
> > >
> 
> > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]
> 
> > > >
> 
> > > > BN: Yes. That is the presumption method.
> 
> > 
> 
> > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable.
> 
> RM: Again, the phrase “external variable” as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. “External variable” does not refer to external reality – it refers to perceptual variables that we take for external reality.Â
> 
> RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment --Â a reality – in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.Â
> 
> RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as _functions_ of the variables in the physical/chemical models of the environment.Â
> 
> RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the “environment” in PCT is the physical model of external reality that comes from the models of physics and chemistry.Â
> 
> RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is _assumed_ to exist in PCT and it exists in PCT as the models of physical sciences.Â
> 
> BestÂ
> 
> Rick
> 
> Â
> 
> > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> 
> > 
> 
> > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> 
> > 
> 
> > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.Â
> 
> > 
> 
> > The best of the season, and a new year coming.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> > 
> 
> > 
> 
> > 
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > 
> 
> > Rick Marken (2017.12.23.1455) –
> 
> > 
> 
> > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > 
> 
> > Yes. That is the presumption method.
> 
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > 
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![rsmarken](http://discourse.iapct.org/user_avatar/discourse.iapct.org/rsmarken/32/3553_2.png) [@rsmarken](http://discourse.iapct.org/u/rsmarken)\
**Post date:** [December 28, 2017, 11:12pm UTC](http://discourse.iapct.org/t/external-variables/13764/15 "2017-12-28T23:12:22Z")

</div>

[From Rick Marken (2017.12.28.1510)]

> **···**
>
> On Wed, Dec 27, 2017 at 10:21 PM, Joh Orengo [joh.orengo@protonmail.com](mailto:joh.orengo@protonmail.com) wrote:
> 
> > > BN: IMO, the physical sciences are necessarily constructivist as well, though they are commonly taken as a basis for one or another flavor of realism…Â
> 
> > >
> 
> > > BN: This is fully compatible with the attitude we have been deriving from PCT, and seems to me to make constructivism necessary.
> 
> > JO: I agree. Models of reality on top of models of reality on top of models…
> 
> RM: PCT looks to me like physical models of one aspect of reality (the environment) _next to_ models control models of different aspect of the the same reality (organisms in that environment). I don’t believe there is any recursion at all.Â
> 
> Best
> 
> Rick
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![Joh\_Orengo](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@Joh\_Orengo](http://discourse.iapct.org/u/Joh_Orengo)\
**Post date:** [December 29, 2017, 8:18am UTC](http://discourse.iapct.org/t/external-variables/13764/16 "2017-12-29T08:18:55Z")

</div>

> Subject: Re: external variables  
> Local Time: December 29, 2017 1:12 AM  
> UTC Time: December 28, 2017 11:12 PM  
> From: rsmarken@gmail.com  
> To: csgnet@lists.illinois.edu
> 
> [From Rick Marken (2017.12.28.1510)]
> 
> > > BN: IMO, the physical sciences are necessarily constructivist as well, though they are commonly taken as a basis for one or another flavor of realism...
> > > 
> > > BN: This is fully compatible with the attitude we have been deriving from PCT, and seems to me to make constructivism necessary.
> > 
> > JO: I agree. Models of reality on top of models of reality on top of models...
> 
> RM: PCT looks to me like physical models of one aspect of reality (the environment) next to models control models of different aspect of the the same reality (organisms in that environment). I don't believe there is any recursion at all.

Rick,

I'm referring to how humans have an indirect perception of reality and what we perceive as reality is basically a model of reality. That model of reality is also situated in an overarching culture (Western civilization, Anglo-American culture, individualist culture, what have you). This culture is basically a model of reality of a model of reality, both of which influences how the other is perceived. This culture coexists and competes with other cultures all of which also contain various sub-cultures that coexist and compete. Different cultures and sub-cultures allot more or less authority to 'science' (reified for this discussion) whose models of reality influence those cultures, sub-cultures, and individuals to varying degrees. Science's physical models of the environment next to control models of the organism in its environment are already situated in models of reality (cultures, sub-cultures) which are situated in a model of reality.

Joh

> **···**
>
> Sent with \<[https://protonmail.com](https://protonmail.com)\>ProtonMail Secure Email.
> 
> > -------- Original Message --------  
> > On Wed, Dec 27, 2017 at 10:21 PM, Joh Orengo \<\<mailto:joh.orengo@protonmail.com\>joh.orengo@protonmail.com\> wrote:
> > 
> > Best
> > 
> > Rick  
> > --  
> > Richard S. Marken
> > 
> > "Perfection is achieved not when you have nothing more to add, but when you  
> > have nothing left to take away.�  
> > --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![bnhpct](http://discourse.iapct.org/user_avatar/discourse.iapct.org/bnhpct/32/34_2.png) [@bnhpct](http://discourse.iapct.org/u/bnhpct)\
**Post date:** [December 29, 2017, 3:21pm UTC](http://discourse.iapct.org/t/external-variables/13764/17 "2017-12-29T15:21:39Z")

</div>

[From Bruce Nevin (2017.12.29.10:14 ET)]

> Rick Marken (2017.12.28.1500) –

Rick, what you said following this question amounts almost to a definition of constructivism.

So let’s make sure we know how the term is defined.

For a constructivist mathematician, what’s valid are constructive proofs and entities that those proofs demonstrate, with the implication that such entities have no independent existence apart from the proofs that demonstrate them.

In education, particularly science education, “constructivism sees learning as a dynamic and social process in which learners actively construct meaning from their experiences in connection with their prior understandings and the social setting.” (Quoted from one of numerous discussions on the web.)

In science:Â

> "Constructivist epistemology is a branch in philosophy of science maintaining that scientific knowledge is constructed by the scientific community, who seek to measure and construct models of the natural world. Natural science therefore consists of mental constructs that aim to explain sensory experience and measurements.

> 

> "According to constructivists, the world is independent of human minds, but knowledge of the world is always a human and social construction. Constructivism opposes the philosophy of objectivism, [which embraces] the belief that a human can come to know the truth about the natural world not mediated by scientific approximations with different degrees of validity and accuracy.

> 

> "According to constructivists there is no single valid methodology in science, but rather a diversity of useful methods."Â

[From Wikipedia “[Constructivist epistemology](https://en.wikipedia.org/wiki/Constructivist_epistemology)” (footnotes suppressed).]

> “The terms “objectivity” and “objectivism” are not synonymous, with objectivism being an ontological theory that incorporates a commitment to the objectivity of objects.” [[Wikipedia again](https://en.wikipedia.org/wiki/Objectivity_(philosophy)#Objectivity_of_knowledge).]

I don’t see how one could understand and accept PCT without having or adopting a constructivist epistemology.

> **···**
>
> RM: In what way is science “constructivist”?Â
> 
> On Thu, Dec 28, 2017 at 6:05 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.28.1500)]
> 
> > Bruce Nevin (2017.12.27.19:44 ET)]
> 
> > > RM:Â Â the “reality” that is assumed to exist on the other side of our senses is the reality of physical science.Â
> 
> > 
> 
> > BN: IMO, the physical sciences are necessarily constructivist as well, though they are commonly taken as a basis for one or another flavor of realism. As I said about corroboration, it’s the best we’ve got (so far).
> 
> RM: In what way is science “constructivist”? I think of science as disciplined imagination; the “imagination” being the theories that are invented to explain what we experience; the “discipline” being the testing of these theories to see if what they predict actually happens. Corroboration is nice – having more than one person agree that the perceived result of an experiment is what was predicted by the theory – but not essential to science. A good scientist, like your friend Einstein and my friends Powers, knows that theories, even when the predict perfectly, are not reality; they are simply our current best approximations to that reality.
> 
> RM: In PCT, we should keep in mind that the physical theories that we use as our models of the environment are just that; models, not reality. Similarly, we should keep in mind that the hierarchical control theory that is used as a model of organisms, is also a model, not reality. It seems to me that people on CSGNet are much better at rejecting the “realism” of the physical model of the than they are at rejecting the realism of the hierarchical control model of the behavior of the organisms that are part of that environment.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > My friend Tom Ryckman, who has researched and written extensively about Einstein, offered this summary statement in a recent [interview](https://www.routledge.com/philosophy/posts/12211?utm_source=Routledge&utm_medium=cms&utm_campaign=170606695):
> 
> > 
> 
> > > Einstein demonstrates that it is possible to be a “realist� about science without adopting the metaphysical presuppositions of what is today called “scientific realism�. In particular, Einstein balanced the aspirational or motivational realist attitude of many working scientists with the clear recognition that realism remains a metaphysical hypothesis, not demonstrable by empirical evidence.
> 
> > 
> 
> > This is fully compatible with the attitude we have been deriving from PCT, and seems to me to make constructivism necessary.
> 
> > 
> 
> > A bit of background: Tom was a student of Zellig Harris (his 1986 dissertation is [here](http://zelligharris.org/Ryckman1991.pdf)). Zellig’s theory of language and information is constructivist and naturalist. His first wife Bruria Kaufmann was Einstein’s mathematical assistant at Princeton, and the three had a friendship. Tom has written two books, _The Reign of Relativity: Philosophy in Physics 1915-1925_ (Oxford) and most recently _Einstein_ (in the Routledge Philosophers series), and he was a co-author with Zellig and others of _The form of information in science_.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Wed, Dec 27, 2017 at 4:02 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.27.1300)]
> 
> On Tue, Dec 26, 2017 at 10:46 PM, Joh Orengo [joh.orengo@protonmail.com](mailto:joh.orengo@protonmail.com) wrote:
> 
> > JO: Rick, If “PCT is based on an epistemology that assumes that we have no direct access to the environment” then it sound like it matches indirect perception/indirect realism, which states that “the world we see around us in  
> > visual consciousness…is merely  
> > a perceptual replica of [the real world (“out there”)] in an internal representation”. Would you say that that is accurate?
> 
> RM: I would say that PCT does say that perception of external reality is _indirect_ in the sense that whatever is “out there” must go through the interface of our senses before it exists as perceptions; indeed, I can’t imagine any theory of perception that is not indirect in this sense. But the PCT model of perception is better called “constructivism” than “realism”. In PCT, perception is not a replica of the real world out there; rather, perception is a function of the variables that physical science tells us makes up the “real world” out there – the environment in which we exist. These functions “construct” our perceptions from the raw material that is the sensed effects of variables in the physical world. They are not a replica of reality since the “reality” that is assumed to exist on the other side of our senses is the reality of physical science. We don’t experience that reality; we experience perceptions that are functions of the sensory effects of that reality. Â
> 
> BestÂ
> 
> Rick
> 
> > (I quoted this from Steven Lehar “The Epistemology of Conscious Experience” at
> 
> > [http://cns-alumni.bu.edu/~slehar/epist/epist.html](http://cns-alumni.bu.edu/~slehar/epist/epist.html))
> 
> > 
> 
> > Joh
> 
> > 
> 
> > 
> 
> > Sent with [ProtonMail](https://protonmail.com) Secure Email.
> 
> > 
> 
> > > -------- Original Message --------
> 
> > > Subject: Re: external variables
> 
> > > Local Time: December 27, 2017 2:25 AM
> 
> > > UTC Time: December 27, 2017 12:25 AM
> 
> > > From: [rsmarken@gmail.com](mailto:rsmarken@gmail.com)
> 
> > > To: csgnet@lists.illinois.edu
> 
> > >
> 
> > > [From Rick Marken (2017.12.26.1620)]
> 
> > 
> 
> –  
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you  
> have nothing left to take away.�  
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> > Bruce Nevin (2017.12.24.13:21 ET)
> 
> > >
> 
> > > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. […]
> 
> > > >
> 
> > > > BN: Yes. That is the presumption method.
> 
> > 
> 
> > BN: And the Test for the Controlled Variable is an especially rigorous form of corroboration–the other method of knowing that a variable is an external variable.
> 
> RM: Again, the phrase “external variable” as it was used by Bill in his letter to Phil refers to perceptual variables that are experienced as being external to us: the color of the walls, the table I work at, the pictures on the wall, etc. “External variable” does not refer to external reality – it refers to perceptual variables that we take for external reality.Â
> 
> RM: PCT is based on an epistemology that assumes that we have no direct access to the environment. But it assumes that there IS an environment --Â a reality – in which we live and this is the environment described by the current models of physics and chemistry. So PCT is a model of both the controller and the environment in which the controller does his controlling. The model of the environment is the models of physics and chemistry; the model of the controller in this environment is the control model.Â
> 
> RM: So the question of whether organisms control environmental variables or perceptual variables is not a question of whether or not there are real variables out in the environment that are controlled. It is a question of how controlled variables are modeled in PCT. And in PCT controlled variables are modeled as _functions_ of the variables in the physical/chemical models of the environment.Â
> 
> RM: Since a function of physical variables is a perceptual variable by definition in PCT then it is always true that what are controlled in PCT are perceptions. But since these perceptions define aspects of the environment (such as area or perimeter of diagonal length) then it is perfectly appropriate to say that a control system controls aspects of the environment (where, again, the “environment” in PCT is the physical model of external reality that comes from the models of physics and chemistry.Â
> 
> RM: It seem like the question of whether control systems control environmental or perceptual variables has turned into a philosophical debate about whether we can know whether or not there is really an environment out there at all. But this question, though philosophically fun, is irrelevant to the question of whether we control environmental or perceptual variables. The environment is _assumed_ to exist in PCT and it exists in PCT as the models of physical sciences.Â
> 
> BestÂ
> 
> Rick
> 
> Â
> 
> > During the time that the disturbance is being applied and resisted, if the investigator has in fact identified the controlled variable, then both the subject and the investigator are controlling the same variable (at different reference values). The confirmation that it is the same variable is an affirmation that the variable exists in a public environment.
> 
> > 
> 
> > By each conflict and collaboration that we experience we less formally corroborate the existence of the external variables that others are simultaneously controlling.
> 
> > 
> 
> > Extending the question, Bill wrote a couple of times on CSGnet about the problem of solipsism. We know it is false, but we can’t prove it. He said “if anyone can find a way out of this, I’d like to know”, or words to that effect. The way out, of course, is each other. Conflict, collaboration, and other forms of collective control affirm not only the existence of external variables, but also the existence of each other. Is that proof? is it proof (that is, secure) against hallucination? I think it’s all we’ve got. Each other. Let’s make the best of it, friends.Â
> 
> > 
> 
> > The best of the season, and a new year coming.
> 
> > 
> 
> > > /Bruce
> 
> > 
> 
> > 
> 
> > 
> 
> > 
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery
> 
> On Sat, Dec 23, 2017 at 10:15 PM, Bruce Nevin [bnhpct@gmail.com](mailto:bnhpct@gmail.com) wrote:
> 
> > [From Bruce Nevin (2017.12.23.22:15 ET)]
> 
> > 
> 
> > Rick Marken (2017.12.23.1455) –
> 
> > 
> 
> > RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. [etc. etc.]
> 
> > 
> 
> > Yes. That is the presumption method.
> 
> On Sat, Dec 23, 2017 at 5:55 PM, Richard Marken [rsmarken@gmail.com](mailto:rsmarken@gmail.com) wrote:
> 
> > [From Rick Marken (2017.12.23.1455)]
> 
> > 
> 
> > Bruce Nevin (2017.12.22.20:20 ET)
> 
> > 
> 
> > BN: We can know that a variable is an external variable in two ways, by presumption and by corroboration.
> 
> RM: I think we know that a variable is an external variable simply by examining our world of experience; what we think of as the real world. Like “behavior”, “external variable” is not a technical term. Bill used it in his letter to Phil because it’s a nice, intuitive way to describe what are known to be perceptual variables based on the epistemology of PCT (“it’s all perception”), but are experienced as features of the world “out there”. For example, in the “What is Size” demo the area of the rectangle looks like a variable aspect of the the world that is “out there”, external to you; an external variable. Of course, we know, from neuroscience and perceptual psychology, that the varying area of the rectangle is a varying neural signal in the brain; a perceptual variable. But once we know that, we can talk about the area of the rectangle as an “external variable” – since it is experienced as such – and count on the fact that anyone who understands PCT will know that we are talking about a perceptual variable (again, since “it’s all perception”).
> 
> RM: What is important about the term “external variable” as a description of our perceptions of the world is the “variable” part. In PCT we recognize that what are controlled are variables – the variables we experience as external reality. So the external world that I am experiencing and controlling – the keys I’m pressing, the characters I make appear on the screen, etc --are actually the states of different perceptual variables. Â
> 
> RM: These “external variables” are presumed to be of different classes – different types - arranged hierarchically; they are the different classes of variables that are presumed to be controlled by the PCT hierarchy of control systems: intensities, sensations, etc. As Bill notes (B:CP, 2nd Edition, p. 155) once you get to a certain level in the hierarchy of controlled variables (the relationship level per B:CP) we pass "… from classes of perception that can be seen as exterior to ourselves to those that seem to be inside ourselves – from the world of “physical reality” to the world of “subjective reality”. So the term “external variable” is really most appropriate for the classes of perception we see as “out there” – the states of the variables that make up my glasses or the flower in the vase; the features of experience that look like “physical reality”. Perceptual variables like the relationship between the glasses and the vase (next to rather than above or below) seem more subjective; they might be be more appropriately called “internal variables” or “cognitive variables”. But in PCT they are all perceptual variables, even though we experience some as being external and other as internal.Â
> 
> RM: I see the main goal of PCT research as mapping out the different classes of perceptual variable that people control and determining the relationship (hierarchical, heterarchical, other?) between them. The perceptual classes described in B:CP, and the hierarchical relationship between them are a _hypothesis_ that Bill came up by examining is own perceptual experience – and he presents evidence for each of the proposed level in B:CP. But this hypothesis – that behavior is the control of different classes of perceptual variable – should be tested; this is what Bill thought should be the main goal of PCT - based research.Â
> 
> BestÂ
> 
> Rick
> 
> > 
> 
> > We know this by presumption all the time, by routinely experiencing our perceptions as “out there” in the environment. Success at adequately controlling our perceptions is generally verification enough.
> 
> > 
> 
> > We know this by corroboration when we perceive that another is controlling the variable that we are controlling.Â
> 
> > 
> 
> > We could be mistaken or deceived about this. The Test for the Controlled Variable verifies that both the tester and the subject are perceiving and controlling the same variable. The tester controls it briefly and circumspectly while introducing disturbances in order to determine whether or not the disturbances are resisted.
> 
> > 
> 
> > > /Bruce
> 
> –
> 
> Richard S. MarkenÂ
> 
> "Perfection is achieved not when you have nothing more to add, but when you
> 
> have nothing left to take away.�
> 
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â --Antoine de Saint-Exupery

---

<div class="post-metadata">

**Author:** ![MartinT](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/m/ee7513/32.png) [@MartinT](http://discourse.iapct.org/u/MartinT)\
**Post date:** [December 29, 2017, 4:55pm UTC](http://discourse.iapct.org/t/external-variables/13764/18 "2017-12-29T16:55:42Z")

</div>

[Martin Taylor 2017.12.29.11.28]

> [From Bruce Nevin (2017.12.29.10:14 ET)]

> 

> > Rick Marken (2017.12.28.1500) –

> ```
> Rick, what you said following this question amounts almost
> 
> ```
> 
> to a definition of constructivism.

> 

> So let’s make sure we know how the term is defined.

> 

> ```
> For a constructivist mathematician, what's valid are
> 
> ```
> 
> constructive proofs and entities that those proofs  
> demonstrate, with the implication that such entities have no  
> independent existence apart from the proofs that demonstrate  
> them.

> 

> ```
> In education, particularly science education,
> 
> ```
> 
> “constructivism sees learning as a dynamic and social  
> process in which learners actively construct meaning from  
> their experiences in connection with their prior  
> understandings and the social setting.” (Quoted from one of  
> numerous discussions on the web.)

> 

> In science:Â

> 

> > ```
> > "Constructivist epistemology is a branch in philosophy
> > 
> > ```
> > 
> > of science maintaining that scientific knowledge is  
> > constructed by the scientific community, who seek to  
> > measure and construct models of the natural world. Natural  
> > science therefore consists of mental constructs that aim  
> > to explain sensory experience and measurements.

> >

> > ```
> > "According to constructivists, the world is independent
> > 
> > ```
> > 
> > of human minds, but knowledge of the world is always a  
> > human and social construction. Constructivism opposes the  
> > philosophy of objectivism, [which embraces] the belief  
> > that a human can come to know the truth about the natural  
> > world not mediated by scientific approximations with  
> > different degrees of validity and accuracy.

> >

> > ```
> > "According to constructivists there is no single valid
> > 
> > ```
> > 
> > methodology in science, but rather a diversity of useful  
> > methods."Â

> 

> [From Wikipedia "[Constructivist epistemology](https://en.wikipedia.org/wiki/Constructivist_epistemology) "  
> (footnotes suppressed).]

> 

> > ```
> > "The terms "objectivity" and "objectivism" are not
> > 
> > ```
> > 
> > synonymous, with objectivism being an ontological theory  
> > that incorporates a commitment to the objectivity of  
> > objects." [[Wikipedia again](https://en.wikipedia.org/wiki/Objectivity_%28philosophy%29#Objectivity_of_knowledge).]

> 

> ```
> I don't see how one could understand and accept PCT
> 
> ```
> 
> without having or adopting a constructivist epistemology.

> 

> > /Bruce

> 

> 

```
All of these definitions are one-sided, looking only at the input

```

side of our interactions with our environment. PCT has a different  
take on the question, which I might call “experimentalist” for lack  
of a better term (“enactivist” nearly does it, but I think it also  
may not be adequate). Here’s a short passage from the introductory  
chapter on “The Environment of Control” of “Powers of Perceptual  
Control.” Earlier in the book I introduced “Oliver”, who is weighing  
something on a classical balance scale that has a pointer that he  
sees to be on one side or the other of a neutral point where the two  
scale pans have equal weight.

```
=========begin quote======

At a higher level than we have yet considered, Oliver may perhaps

```

see the pans, their contents, and the pointer all together as a  
configuration, but why should he be justified in assuming that in  
some outer world there is a real pan with real weights, and that his  
perception of the “heavy-or-light� location of the scale pointer  
represents a property of a real scale pointer that indicates  
something about a property of another scale pan and its contents? Is  
he so justified?

```
There are two opposed facile answers to this. One is “You have

```

access only to your perceptions, and can know nothing about the  
world that appears to be ‘out there’ since your perceptions might be  
created by something entirely different, such as a manipulative  
super-intelligence.� The other is “The world is whatever it happens  
to be, and what you perceive is what it is for you, but perhaps for  
nobody else.� Neither answer is really helpful, though both may be  
true. Let us contemplate a different kind of answer, perhaps no more  
true, but perhaps more useful.

```
Although we could never prove it, we must act as though our

```

perceptions are not entirely self-referential (solipsistic) or  
created at need by some super-being, and as though we are not merely  
inhabitants of some grand super-software simulation project. We must  
also assume that there is a distinction between what we perceive and  
what there is to be perceived — that there is a “real wworldâ€? of  
which we are a distinct part, separate from the rest of the world.  
What happens in the real world sometimes alters the tiny part of it  
that affects our perceptual apparatus, and how we act sometimes  
influences a little of what happens in the part outside of us, our  
“environment�. If these assumptions are wrong, we cannot know that  
they are wrong, so there is no point in discussing that possibility.  
We must act as though the assumptions are correct.

```
Given the basic reality and separability assumptions, we can say a

```

surprising amount about what is in our real-world environment. For  
example, Oliver can say that no matter what the “weights� and “scale  
pointer� really are, if he perceives himself to be adding or  
subtracting “weights�, the “scale pointer� will change its angle  
consistently from one side of vertical to the other depending on  
whether he is adding or subtracting weights. It rarely changes from  
“too heavy� to “too light� when he adds a weight, or the reverse  
when he subtracts a weight.

```
More generally, we often find consistencies between what we do and

```

what changes in what we perceive. Few of these consistencies are  
always observed, and some happen in contexts we rarely encounter,  
but many happen almost always in frequently encountered  
circumstances. We perceive something being put onto our outstretched  
hand and feel weight on that hand. A stage magician might be able to  
arrange conditions in which this didn’t happen, but usually it does.  
We throw something into the air and perceive it to rise and then  
fall. We put it on a table and perceive that it stays there, while  
the perception of weight in the hand is reduced. Assuming that there  
is a real world out there, something about the interactions between  
it and our senses creates these normally observed consistencies.  
When they don’t happen, we seek explanations for why they don’t  
rather than thinking we were wrong to expect them to happen.

```
Perceptual Control Theory (PCT) is based in the philosophically

```

obvious fact that if there is a “real world out there�, we can know  
of it only what we obtain through our senses. As we said above, we  
assume that the “real action� is in the “real world� outside our  
bodies, and thereafter simply treat it as a given that the real  
world has effects on our sensory systems and is acted on by our  
muscular and chemical (and for some species electrical) outputs.  
What happens in the real world, whether we can perceive it or not,  
determines whether we live or die, are sickened by radiation  
poisoning, bruised by hits from hard objects, are well nourished by  
our food, enjoy good social relations, and so forth.

```
Whatever is in the real world, our interactions with it have allowed

```

us to stay alive long enough to be able to perceive these little  
consistencies and our ancestors to stay alive long enough to  
propagate their genes into their descendants, including us. We can  
perform certain actions and expect certain things to happen, which  
would not be the case if our perceptions were entirely divorced from  
what is “really� out there. In particular, if we can control a  
perception such as the angle of Oliver’s scale pointer by acting on  
the environment, that in itself is evidence (under our basic  
assumption) that our perception corresponds to something in the real  
world. We do what in a laboratory would be called “experimenting�,  
influencing the environment in different ways and seeing what  
happens.

```
==========end quote=========

PCT takes not so much a constructivist view of the world as an

```

experimentalist view. What we perceive depends in large part on the  
consistency of relationships among the parts of the world nearby in  
space and time, and on how they interact when we act on them. When I  
calculated the likelihood of prespecified small static patterns  
occurring in a tiny toy universe of black and white squares on a  
double-sized chessboard, the numbers were astonishing, verging on  
one in the number of atoms in the visible Universe for simple  
patterns of say 25 black square cross on a white 15x15 field.

```
Since the perceived Universe is much more complex than my little

```

chessboard array, it would be beyond belief (literally) that the  
structures we produce in our perceptual functions are not either  
constructed for us by control systems (like the Ames Room) or are  
really out there in the real environment, to be used by successive  
levels of perceptual functions of increasing complexity, and tested  
by control.

```
Martin

```

> **···**
>
> RM: In what way is science “constructivist”?Â

---

<div class="post-metadata">

**Author:** ![EetuP](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/e/df705f/32.png) [@EetuP](http://discourse.iapct.org/u/EetuP)\
**Post date:** [December 29, 2017, 7:31pm UTC](http://discourse.iapct.org/t/external-variables/13764/19 "2017-12-29T19:31:52Z")

</div>

[Eetu Pikkarainen 2017-12-29]

Good points. We have a very old and strong division in philosophy between realism and idealism – namely epistemological realism and iddealism. Roughly the first says  
that our knowledge is based on the objects of that knowledge. The objects have a strong role in determining the knowledge. The second gives no role to any external or separate objects but instead it is knowing or mental itself which determines knowledge. Constructivism  
is a modern trial to solve the dispute by accepting both the role of the object and the activity of the subject. But as a compromise, constructivism sways still between realism and idealism. Basically constructivism (from Kant) has been understood so that  
external objects somehow affect our senses and from these (vague and formless) effects we construct the determinate form of our knowledge. The problem here is that the active role given to the knowing subject consists only of “mental� activity of knowledge  
production. It is still a one way process from out to in. The “real� constructive activity by which we affect and even construct the objects of our environment is wholly forgotten. It is just the two way circular theory of action (PCT) which finally could  
make it understandable what are the roles of the object and the subject in knowing. Thus the theory of knowledge is part of the theory of action. Constructivism as such is a lame duck but PCT could teach it to walk.

> **···**
>
> Eetu
> 
> [Martin Taylor 2017.12.29.11.28]
> 
> > [From Bruce Nevin (2017.12.29.10:14 ET)]
> 
> > > Rick Marken (2017.12.28.1500) –
> 
> > > RM: In what way is science “constructivist”?
> 
> > Rick, what you said following this question amounts almost to a definition of constructivism.
> 
> > So let’s make sure we know how the term is defined.
> 
> > For a constructivist mathematician, what’s valid are constructive proofs and entities that those proofs demonstrate, with the implication that such entities have no independent existence apart from the proofs that demonstrate  
> > them.
> 
> > In education, particularly science education, “constructivism sees learning as a dynamic and social process in which learners actively construct meaning from their experiences in connection with their prior understandings  
> > and the social setting.” (Quoted from one of numerous discussions on the web.)
> 
> > In science:
> 
> > > "Constructivist epistemology is a branch in philosophy of science maintaining that scientific knowledge is constructed by the scientific community, who seek to measure and construct models of the natural world. Natural  
> > > science therefore consists of mental constructs that aim to explain sensory experience and measurements.
> 
> > > "According to constructivists, the world is independent of human minds, but knowledge of the world is always a human and social construction. Constructivism opposes the philosophy of objectivism, [which embraces] the  
> > > belief that a human can come to know the truth about the natural world not mediated by scientific approximations with different degrees of validity and accuracy.
> 
> > > “According to constructivists there is no single valid methodology in science, but rather a diversity of useful methods.”
> 
> > [From Wikipedia "[ Constructivist  
> > epistemology](https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FConstructivist_epistemology&data=02%7C01%7C%7Cbcc7c586b9604cbf9b8508d54edd0b54%7C9f9ce49a51014aa38c750d5935ad6525%7C0%7C0%7C636501633646084750&sdata=vbhAAD8tdpEDRLbq0%2BpD5ZX8KcCbkFlFuGx00jdzhNY%3D&reserved=0)" (footnotes suppressed).]
> 
> > > “The terms “objectivity” and “objectivism” are not synonymous, with objectivism being an ontological theory that incorporates a commitment to the objectivity of objects.” [[ Wikipedia  
> > > again](https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FObjectivity_%2528philosophy%2529%23Objectivity_of_knowledge&data=02%7C01%7C%7Cbcc7c586b9604cbf9b8508d54edd0b54%7C9f9ce49a51014aa38c750d5935ad6525%7C0%7C0%7C636501633646084750&sdata=2VuSQmBWCsPWJ2nVPQFt33jwoK61xZQvMMrs5JVaPTQ%3D&reserved=0).]
> 
> > I don’t see how one could understand and accept PCT without having or adopting a constructivist epistemology.
> 
> > /Bruce
> 
> All of these definitions are one-sided, looking only at the input side of our interactions with our environment. PCT has a different take on the question, which I might call “experimentalist”  
> for lack of a better term (“enactivist” nearly does it, but I think it also may not be adequate). Here’s a short passage from the introductory chapter on “The Environment of Control” of “Powers of Perceptual Control.” Earlier in the book I introduced “Oliver”,  
> who is weighing something on a classical balance scale that has a pointer that he sees to be on one side or the other of a neutral point where the two scale pans have equal weight.
> 
> =========begin quote======
> 
> At a higher level than we have yet considered, Oliver may perhaps see the pans, their contents, and the pointer all together as a configuration, but why should he be justified in assuming that in some outer world there is a real pan with real weights, and that  
> his perception of the “heavy-or-light� location of the scale pointer represents a property of a real scale pointer that indicates something about a property of another scale pan and its contents? Is he so justified?
> 
> There are two opposed facile answers to this. One is “You have access only to your perceptions, and can know nothing about the world that appears to be ‘out there’ since your perceptions might be created by something entirely different, such as a manipulative  
> super-intelligence.� The other is “The world is whatever it happens to be, and what you perceive is what it is for you, but perhaps for nobody else.� Neither answer is really helpful, though both may be true. Let us contemplate a different kind of answer,  
> perhaps no more true, but perhaps more useful.
> 
> Although we could never prove it, we must act as though our perceptions are not entirely self-referential (solipsistic) or created at need by some super-being, and as though we are not merely inhabitants of some grand super-software simulation project. We must  
> also assume that there is a distinction between what we perceive and what there is to be perceived — that there is a “real worldâ€? of which we are a distinct part, separate from the rest of the world. What happens in the real world sometimes alters the tiny  
> part of it that affects our perceptual apparatus, and how we act sometimes influences a little of what happens in the part outside of us, our “environment�. If these assumptions are wrong, we cannot know that they are wrong, so there is no point in discussing  
> that possibility. We must act as though the assumptions are correct.
> 
> Given the basic reality and separability assumptions, we can say a surprising amount about what is in our real-world environment. For example, Oliver can say that no matter what the “weights� and “scale pointer� really are, if he perceives himself to be adding  
> or subtracting “weights�, the “scale pointer� will change its angle consistently from one side of vertical to the other depending on whether he is adding or subtracting weights. It rarely changes from “too heavy� to “too light� when he adds a weight, or the  
> reverse when he subtracts a weight.
> 
> More generally, we often find consistencies between what we do and what changes in what we perceive. Few of these consistencies are always observed, and some happen in contexts we rarely encounter, but many happen almost always in frequently encountered circumstances.  
> We perceive something being put onto our outstretched hand and feel weight on that hand. A stage magician might be able to arrange conditions in which this didn’t happen, but usually it does. We throw something into the air and perceive it to rise and then  
> fall. We put it on a table and perceive that it stays there, while the perception of weight in the hand is reduced. Assuming that there is a real world out there, something about the interactions between it and our senses creates these normally observed consistencies.  
> When they don’t happen, we seek explanations for why they don’t rather than thinking we were wrong to expect them to happen.
> 
> Perceptual Control Theory (PCT) is based in the philosophically obvious fact that if there is a “real world out there�, we can know of it only what we obtain through our senses. As we said above, we assume that the “real action� is in the “real world� outside  
> our bodies, and thereafter simply treat it as a given that the real world has effects on our sensory systems and is acted on by our muscular and chemical (and for some species electrical) outputs. What happens in the real world, whether we can perceive it  
> or not, determines whether we live or die, are sickened by radiation poisoning, bruised by hits from hard objects, are well nourished by our food, enjoy good social relations, and so forth.
> 
> Whatever is in the real world, our interactions with it have allowed us to stay alive long enough to be able to perceive these little consistencies and our ancestors to stay alive long enough to propagate their genes into their descendants, including us. We  
> can perform certain actions and expect certain things to happen, which would not be the case if our perceptions were entirely divorced from what is “really� out there. In particular, if we can control a perception such as the angle of Oliver’s scale pointer  
> by acting on the environment, that in itself is evidence (under our basic assumption) that our perception corresponds to something in the real world. We do what in a laboratory would be called “experimenting�, influencing the environment in different ways  
> and seeing what happens.
> 
> ==========end quote=========
> 
> PCT takes not so much a constructivist view of the world as an experimentalist view. What we perceive depends in large part on the consistency of relationships among the parts of the world nearby in space and time, and on how they interact when we act on them.  
> When I calculated the likelihood of prespecified small static patterns occurring in a tiny toy universe of black and white squares on a double-sized chessboard, the numbers were astonishing, verging on one in the number of atoms in the visible Universe for  
> simple patterns of say 25 black square cross on a white 15x15 field.
> 
> Since the perceived Universe is much more complex than my little chessboard array, it would be beyond belief (literally) that the structures we produce in our perceptual functions are not either constructed for us by control systems (like the Ames Room) or  
> are really out there in the real environment, to be used by successive levels of perceptual functions of increasing complexity, and tested by control.
> 
> Martin

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<div class="post-metadata">

**Author:** ![Joh\_Orengo](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/j/8baadc/32.png) [@Joh\_Orengo](http://discourse.iapct.org/u/Joh_Orengo)\
**Post date:** [December 29, 2017, 7:42pm UTC](http://discourse.iapct.org/t/external-variables/13764/20 "2017-12-29T19:42:21Z")

</div>

Constructivism as such is a lame duck but PCT could teach it to walk.

> **···**
>
> > Eetu
> 
> Ha! I like this!
> 
> Joh

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