On McRae's Hume

167. ON McRAE' S HUME Professor McRae ' s interesting paper may be rather naturally divided into two parts. In the first part he explains what he takes Hume's account of time to be; in the second he advances the bold thesis that Hume's account of time, or perhaps of duration, provides a basis or foundation for his more widely discussed remarks on identity, substance, the self, the necessary connections. In what follows I first reconstruct Professor McRae' s paper, and then I raise some problems, perhaps puzzles, about Hume's view on duration, time and fictions. According to McRae, some philosophers (Descartes, Spinoza, Leibniz) distinguish between time and duration, both of which are taken to be perfectly legitimate notions. Hume, by contrast, takes time and duration to be the same, viz. , a succession of moments. What philosophers and the vulgar call 'duration' is something quite different, namely a single unbroken stretch of time which is not composed of successive parts. Of duration taken in this latter way, McRae says, Hume has four things to say, all of them negative: (1) we have no idea of duration; (2) no object has duration; (3) there is no such thing as duration; and (4) duration is a fiction. Properly understood as a succession of moments, however, time certainly exists and is thus not a fiction. Moreover, we have the or at least an idea of time, despite the fact that it is obtained without derivation from a precedent impression. And, while no object can be said to have time, Hume will nonetheless allow that objects exist at certain times and perhaps across a time span. In the second part of his paper, Professor McRae distinguishes two types of Humean fictions. The first arises when one idea is confused with another and mis-applied to some object. The second arises when the imagination creates an "idea" in the attempt to resolve a 168. contradiction which comes up when the first fiction is applied to an object. What I have called McRae' s "bold thesis" in the second part of his paper can now be stated. Duration, or the putative idea thereof, is a fiction of the first type, one that is attributed to what Hume calls "steadfast objects." However, such an object can be considered in two ways. One might consider the object at two stages of this duration and, McRae says, "...this will give us the idea of number" (p. 126); or, one might consider in turn a series of objects, each of them supposedly "steadfast," all along supposing that though time is changing, the objects are not, and "...in this way- we get the idea of unity" (Ibid.) . But no object is both a unity and a multiplicity. So, to reconcile these conflicting considerations, the "idea" or fiction of identity is invented. As McRae says: "The idea of identity is a pure product of the imagination invented to mediate between unity and number" (Ibid. ) . This invented "idea" is then mis-applied (a fiction of type one) to interrupted appearances of an object. To reconcile the supposed identity of an object with successive appearances of it, the fiction of substance is invented. Quoting both McRae and Hume, In order to reconcile the contradiction between identity and diversity, the imagination is apt to feign something unknown and invisible, which it supposes to continue the same under all these variations ; 2 and this unintelligible something it calls a substance. . . (p. 128). Related needs to resolve contradictions, on McRae' s account, lead to the fictions of the self (p. 128) and of necessary connections (p. 130), though the latter fiction is of type one. Hence, McRae' s "bold thesis" amounts to this: Duration is a fiction. In the attempt to apply this fiction , one is led to, logically led to, most, if not all, of the other famous Humean fictions. And, if we allow that there are mental acts, for Hume, as well as impressions and ideas, "...then a fictitious duration will be attributed to 169. objects and by a progressive compounding of fictitious mental actions will give the world the ontological structure which it has for the vulgar belief we all share. It...