Chapter 10 - Grasping Sameness

Summary

INTRODUCTION: IMAGES OF IDENTITY

In Subject and Predicate in Logic and Grammar, Strawson (1974) offers “a picture or model” of what happens when a man learns that two things formerly thought to be separate are in fact one and the same. “We are to picture a [knowledge] map, as it were” on which all those individuals the man knows of are represented by dots, and the predicates the man knows to apply to each are written in lines emanating from these dots or, if the predicate is relational, lines joining two dots.

Now when [the man] receives what is for him new information … he incorporates [this] by … making an alteration on his knowledge map [for example,] he draws a further line between two dots. But when it is an identity statement containing two names from which he receives new information, he adds no further lines. He has at least enough lines already; at least enough lines and certainly one too many dots. So what he does is to eliminate one dot of the two, at the same time transferring to the remaining one … all those lines and names which attach to the eliminated dot. (Strawson 1974, pp. 54–5.)

On Strawson's picture, the identity of a particular is represented in the mind by the identity of another particular. So long as you haven't made any mistakes, everything you know about your mother is attached to the same particular mental representation of your mother, to the same token.