[from Gary Cziko 970402.1626 GMT]
PCTists often point out the problems of cause-effect thinking for
understanding behavior by explaining that causes are simultaneously effects
and effects are simultaneously causes.
To see an interesting graphic illustration of this ambiguity, check out
http://www.prairienet.org/~punya/ambigrams/ and click on "cause-effect."
You can also click on "cziko" if you want to see what I look like
upside-down (much the same).
--Gary