Time and the Idea of Time

205 TIME AND THE IDEA OF TIME Hume entitled Part II of Book I of the Treatise "Of the Ideas of Space and Time." Students of this most obscure Part of the Book are aware, however, that he spends little time in it on time. The main reason for his concentration on space. is polemical. In Part II his primary object is to exhibit the contradictions and absurdities implicit in the science of his day with its postulation of empty space and of the mathematics with its notion of infinite divisibility, and then to show how these difficulties can be overcome by the adoption and implementation of the theory of ideas he had developed in Part I. As a result, with the exception of a discussion that occupies approximately three pages in Section III, most of his references to time in Part II are little more than brief appendages tacked on to his arguments concerning space. Hume commentators have generally taken their cue from him. Although the literature contains substantial analyses of his views about space, very little can be found on the subject of time. In this paper, I shall attempt to add something to that slim literature. As its title indicates, this paper will be concerned with two subjects, time and the idea of time. Hume accepts the ordinary distinction between thé two. Time and our idea of time are separate realities, the former being a part of the world independent of us and the latter being a part of the content of our consciousness. I shall observe this distinction, beginning with an account of what Hume means by time and following that with an explanation of his theory of the origin and nature of the idea of time. After finishing these two expository sections I shall devote 206 the remainder of the paper to a critical examination of Hume's views on both subjects, ending with a suggestion about a possible alternative route he might have followed in his argument about time and the idea of time in Part II . A final preliminary point: Although Hume devotes most of his attention to space in Part II, he makes it clear that, because space and time (as well as our ideas of them) are analogous to each other in certain vital respects, his views concerning the former can easily be transferred and applied to the latter. 1. Time Hume states or implies several things about the nature of time in Part II. (1)He equates time with duration, treating the two terms as equivalent throughout his discussion. (2)Time is an objective reality, or aspect of the external world. This interpretation may be questioned because Hume never asserts an objectivistic view of time unequivocally and in certain passages writes in a way that could be interpreted as implying that time is a characteristic of our conscious experience. "As 'tis from the disposition of visible and tangible objects we receive the idea of space, so from the succession of ideas and impressions we form the idea of time..." (T 35). But later he writes: "...time is nothing but the manner, in which some real objects exist..." (T 64). Also, in the titles of his first two sections he makes a clear distinction, labelling Section I "Of the infinite divisibility of our ideas of space and time" and Section II "Of the infinite divisibility of space and time." Since, in Section II, it is apparent that he is talking about space as a part 207 of the external world, the natural inference is that he is talking about time in the same way, as, for example, when he writes, "The infinite divisibility of space implies that of time, as is evident from the nature of motion" (T 31). (3)Time is not infinitely divisible but is made up of parts Hume calls 'moments' (T 31). These moments are the 'building blocks' of time and are ultimate and indivisible. They are analogous to the ultimate, indivisible parts of space, which Hume labels 'mathematical points' (T 40). (4)The moments of time are not co-existent but successive. In this respect time differs from space. "'Tis also evident, that these parts [of...