Xref: utzoo comp.ai:3048 talk.philosophy.misc:1808 sci.lang:3884 Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!iuvax!rutgers!elbereth.rutgers.edu!harnad From: harnad@elbereth.rutgers.edu (Stevan Harnad) Newsgroups: comp.ai,talk.philosophy.misc,sci.lang Subject: Re: Categorization Summary: On the primacy of all-or-none categories and boolian features Message-ID: Date: 11 Jan 89 06:00:52 GMT References: <2980@uhccux.uhcc.hawaii.edu> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 35 In Article 3140 of comp.ai, lee@uhccux.uhcc.hawaii.edu (Greg Lee) of University of Hawaii asks: " Why does T presuppose a mechanism for C? Because to judge how typical an X an X is I must first be able to judge that it's an X. " If 40%-X and 89%-X are grades, then so is 100%-X a grade. " If you have T, C can be described as a special case of it. 40% what? 89% what? If you don't have a 100% category in the first place for whatever you have a graded quantity of, you have an incoherent concept or an infinite regress. Suppose gold was, by its nature, an alloy, i.e., K% lead and (100 - k)% "gold." Now what was that SECOND stuff I just mentioned? (Once you have C, T can be described as a special case of it, not vice versa.) " if a feature is any function whatever of perceptible things in the " input (past and present), including perhaps disjunctions, weightings, " etc., then you could say that since someone performed a categorization, " there must have been some things he noticed, a "feature", that allowed " him to do so. This empty argument might reasonably be taken to be a " reductio ad absurdum for allowing anything at all to count as a feature. On the contrary, I think it's a QED, and one that those who have been caught up in the Roschian view ought to take a careful look at (when the categorization is reliable rather than just a lucky guess). -- Stevan Harnad INTERNET: harnad@confidence.princeton.edu harnad@princeton.edu srh@flash.bellcore.com harnad@elbereth.rutgers.edu harnad@princeton.uucp BITNET: harnad@pucc.bitnet CSNET: harnad%princeton.edu@relay.cs.net (609)-921-7771