5. Concepts are public, they’re the sorts of things that lots of people can, and do, share.
Since, according to RTM, concepts are symbols, they are presumed to satisfy a type/token relation; to say that two people share a concept (i.e. that they have literally the same concept) is thus to say that they have tokens of literally thesame concept type. The present requirement is that the conditions for typing concept tokens must not be so stringentas to assign practically every concept token to a different type from practically any other.
I put it this way advisedly. I was once told, in the course of a public discussion with an otherwise perfectly rational and civilized cognitive scientist, that he “could not permit” the concept HORSE to be innate in humans (though I guess it’s OK for it to be innate in horses). I forgot to ask him whether he was likewise unprepared to permitneutrinos to lack mass.Just why feelings run so strongly on these matters is unclear to me. Whereas the ethology of all other species is widely agreed to be thoroughlyempirical and largely morally neutral, a priorizing and moralizing about the ethology of our species appears to be the order of the day. Very odd.
It seems pretty clear that all sorts of concepts (for example, DOG, FATHER, TRIANGLE, HOUSE, TREE, AND, RED, and, surely, lots of others) are ones that all sorts of people, under all sorts of circumstances, have had andcontinue to have. A theory of concepts should set the conditions for concept possession in such a way as not to violatethis intuition. Barring very pressing considerations to the contrary, it should turn out that people who live in verydifferent cultures and/or at very different times (me and Aristotle, for example) both have the concept FOOD; andthat people who are possessed of very different amounts of mathematical sophistication (me and Einstein, forexample) both have the concept TRIANGLE; and that people who have had very different kinds of learningexperiences (me and Helen Keller, for example) both have the concept TREE; and that people with very differentamounts of knowledge (me and a four-year-old, for example) both have the concept HOUSE. And so forth.Accordingly, if a theory or an experimental procedure distinguishes between my concept DOG and Aristotle’s, orbetween my concept TRIANGLE and Einstein’s, or between my concept TREE and Helen Keller’s, etc. that is a verystrong prima facie reason to doubt that the theory has got it right about concept individuation or that the experimentalprocedure is really a measure of concept possession.
I am thus setting my face against a variety of kinds of conceptual relativism, and it may be supposed that my doing so is itself merely dogmatic. But I think there are good grounds for taking a firm line on this issue. Certainly RTM isrequired to. I remarked in Chapter 1 that RTM takes for granted the centrality of intentional explanation in any viablecognitive psychology. In the cases of interest, what makes such explanations intentional is that they appeal to coveringgeneralizations about people who believe that such-and-such, or people who desire that so-and-so, or people whointend that this and that, and so on. In consequence, the extent to which an RTM can achieve generality in theexplanations it proposes depends on the extent to which mental contents are supposed to be shared. If everybodyelse’s concept WATER is different from mine, then it is literally true that only I have ever wanted a drink of water, andthat the intentional generalization ‘Thirsty people seek water’ applies only to me. (And, of course, only I can state thatgeneralization; words express concepts, so if your WATER concept is different from mine, ‘Thirsty people seek water’means something different when you say it and when I do.) Prima facie, it would appear that any very thoroughgoingconceptual relativism would preclude intentional generalizations with any very serious explanatory power. This holdsin spades if, as seems likely, a coherent conceptual relativist has to claim that conceptual identity can’t be maintainedeven across time slices of the same individual.