Hume on Identity

18. HUME ON IDENTITY The analysis of identity which Hume presents in the Treatise of Human Nature is in large part a development out of the author's view of time and its relation to objects. Here I will attempt to trace through this analysis and to assess its cogency. I will try to show that Hume's view of time, and the doctrine of identity which stems from it, are largely independent of the author's representationalism and his impressions-ideas epistemology; I will also try to clarify the connection, or lack of connection, between Hume's general doctrine of identity and his remarks on personal identity near the end of Book I of the Treatise. Regarding the analysis of identity itself, I will argue that this account falls through because Hume bases it on a certain view of time, and then is forced to reject covertly this doctrine of time in his explanation of how we acquire the concept of identity. There are some brief remarks about identity in Part III of Book I, where Hume lists identity as one of the seven kinds of philosophical relation, but this topic is not explored in any detail until Part IV. This serious treatment of identity, however, unlike the perfunctory remarks in Part III, draws heavily on the theory of space and time which is developed in Part II , so it is this doctrine which we must first consider. Although it is not possible here to enter into a detailed analysis of Hume's arguments regarding space and time, we must have at least a brief look at them simply to see what Hume's view of space and time is, so that we may see how he applies this to identity. Hume's treatment of this topic falls into two main sections. First, he is concerned to show that any quantity of space or time must be composed of a finite number of indivisible parts. He then attempts to prove that these indivisible parts must be particular objects, and that space and time just are these objects in their different modes of arrangement or presentation. 19. Of his arguments against the infinite divisibility of space and time, one of them at least does not hinge at all on what I shall call Hume's representationalism, his view that we are directly aware only of our own mental contents , and that any knowledge of things other than these "perceptions" must be the result of an inference of some kind. This argument begins with the premise that . . .existence in itself belongs only to unity, and is never applicable to number, but on account of the unites, of which the number is 2 composed. (T30) If space and time were infinitely divisible, however, there would be no units, for any part of space or length of time which was chosen, however small, would be a complex composed of smaller parts. Thus if space and time were infinitely divisible, there would be no units of which they were composed , and thus space and time as aggregates of units could not exist either. So if space and time exist at all, they must be composed of indivisible parts. Although Hume claims to have derived this "strong and beautiful" argument from a French philosopher named Malezieu, it could also be regarded as an application to space and time of Leibniz' argument in the Monadology that 3 reality must consist of monads. It would be interesting to know in this connection how familiar Hume (or Malezieu) was with the writings of Leibniz. At any rate, this is perhaps the most powerful argument of Part II, even though it is hardly original with Hume. Having established to his satisfaction in the first two sections of Part II that space and time are composed of indivisible parts, Hume attempts in the third section to show that these parts must be objects, more specifically colored points, and that space and time simply are these points in two different modes of arrangement. Hume begins this argument by reminding the reader that every idea first makes its appearance in a correspondent impression. (T33) 20. He then asks from what impressions our...