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Public_Heretic comments on Where to Draw the Boundary? - Less Wrong

36 Post author: Eliezer_Yudkowsky 21 February 2008 07:14PM

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Comment author: Public_Heretic 23 February 2008 07:47:48PM 1 point [-]

"You cannot hide behind a comforting shield of correct-by-definition. Both extensional definitions and intensional definitions can be wrong, can fail to carve reality at the joints. "Categorizing is a guessing endeavor, in which you can make mistakes; so it's wise to be able to admit, from a theoretical standpoint, that your definition-guesses can be "mistaken"."

I agree heartily with most of this post, but it seems to go off the rails a bit at the end in the section I quote above. Eliezer says intensional definitions (that is, categorizations based on the arbitrary highlighting of certain dimensions as salient) can be "wrong" (i.e. untrue) because they fail to carve reality at the joints. But reality, in its full buzzing and blooming confusion, contains an infinite numbers of 'joints' along which it could be carved. It is not at all clear how we could say that focusing one some of those joints is "true" while focusing on other joints is "false," since all such choices are based on similarly arbitrary conventions.

Now, it is certainly true that certain modes of categorization (i.e. the selection of certain joints) have allowed us to make empirical generalizations that would not otherwise have been possible, whereas other modes of categorization have not yielded any substantial predictive power. But why does that mean that one categorization is "wrong" or "untrue"? Better would seem to be to say that the categorization is "unproductive" in a particular empirical domain.

Let me make my claim more clear (and thus probably easier to attack): categories do not have truth values. They can be neither true nor false. I would challenge Eliezer to give an example of a categorization which is false in and of itself (rather than simply a categorization which someone then used improperly to make a silly empirical inference).