speeds that are either too fast or too slow for us to notice. The express purpose of the section is to argue that our primary sense of duration arises from the internal succession of ideas, rather than from our registering of external moving objects. But as Locke presents an example, he turns to redefining the instant in such a way that incorporates it as a part of time even as its extensity cannot be measured.
Here is what Locke has to say about the situation of being shot—his example of succession too fast for us to register cognitively:
Let a Cannon-Bullet pass through a Room, and in its way take with it any Limb, or fleshy Parts of a Man; ’tis as clear as any Demonstration can be, that it must strike successively the two sides of the Room: ’Tis also evident, that it must touch one part of the Flesh first, and another after; and so in Succession: And yet I believe, no Body, who ever felt the pain of such a shot, or heard the blow against the two distant Walls, could perceive any Succession, either in the pain, or sound of so swift a stroke. Such a part of Duration as this, wherein we perceive no Succession, is that which we may call an Instant; and is that which takes up the time of only one Idea in our Minds, without the Succession of another, wherein therefore we perceive no Succession at all. (185)
Locke’s assertion that “no Body, who ever felt the pain of such a shot, or heard the blow against the two distant Walls, could perceive any Succession, either in the pain, or sound of so swift a stroke” serves a crucial double purpose here. On the one hand, Locke argues that without the perception of succession such an instance can only yield an instant—“that which takes up the time of only one Idea in our Minds.” On the other hand, his prose highlights a succession of dramatic events and their strong impact on the body—the “pain” and the “blow”—which cannot but evoke some temporal dimension through which and in which the wounded person experiences his endurance. And it is precisely this drama—the event of being shot, highlighted through discursive succession even as, or precisely because, the represented body cannot gauge this succession—that leads Locke to redefine the instant as “a part of time.” Recall that the opening paragraphs of his discussion of time define our primary sense of duration as succession—as the difference between one idea and another: “We have no perception of Duration, but by considering the train of Ideas, that take their turns in our Understandings. When that succession of Ideas ceases, our perception of Duration ceases with it” (182). By this initial logic, the instant, the single idea, is atemporal. However, by the second definition—the instant in the example of being shot—a single idea is already a temporal element—“that which takes up the time of only one Idea.” In the next chapter Locke reiterates the second definition, the one that conceives of the instant— which here he calls a moment—as a part of duration. “Such a small part in Duration,” he writes, “may be called a Moment, and is the time of one Idea in our Minds” (203). Thus the example of being shot prompts Locke to revise his initial account of our primary sense of duration to include the instant. And this revision suggests, in turn, that we might have an idea of duration that does not pertain to extensity and cannot be measured. Though duration can’t be counted when we are shot or when we hold a single idea in our minds, though we cannot tell time’s length from firsthand sensations on such occasions, we do have some temporal notion—the instant or the moment—crucial to our persisting endurance through such events. And if the quantity or extensity of such moments cannot be assessed, their quality or intensity seems unavoidable. At stake here is an immeasurable moment that cannot be subtracted from endurance. I think therefore I endure—“the Continuation of the Existence of our selves” with which Locke began his chapters on duration—thus turns out to be “Commensurate to the succession of any Ideas in our Minds,” with an emphasis falling on “any” more than on “succession.” Any single idea turns out to be key to our sense of duration insofar as its qualities inescapably graft themselves on our minds and bodies and even as its quantities remain unknown.
Locke’s discussion, then, points up qualitative dimensions of durational experience that his explicit argument cannot account for. These qualitative dimensions arise from irregularities of succession and from intensities of sensations, aspects of “the succession of ideas” whose impact on our sense of duration Locke considers only indirectly. In Hume’s A Treatise of Human Nature (1738), however, these dimensions take center stage. Far more than Locke, Hume focuses on differentiating between “degrees and force of liveliness,” as Hume puts it throughout the first chapter of the Treatise. Hume distinguishes between impressions and ideas and devotes much attention to the passions, which he takes to deliver impressions of the strongest degree, in contrast to “the faint images of these in thinking and reasoning,” (1), which he calls ideas.”8 Hume also examines the logic of association among impressions and ideas much more thoroughly than Locke does. Whereas Locke posits succession as a singular principle requiring little analysis and devotes only one chapter to the association of ideas in which he primarily focuses on the dangers of chance connections, Hume argues that resemblance, contiguity, and cause and effect are all principles that universally and naturally encourage our relating one idea or impression to another thus complexly shaping thoughts and feelings (11).9 Hume proposes that such associative operations are responsible for both the diachronic movement of our minds—the succession of our ideas and impressions—and the synchronic resonances that reverberate in the mind at a single instant—the complex ideas and passions that yoke together a number of impressions and ideas into coherent notions of substance or mode.10 Furthermore, he distinguishes between the ways by which ideas connect to one another and the ways by which impressions do, arguing that “ideas are associated by resemblance, contiguity, and causation; and impressions only by resemblance” (283). For Hume, then, our minds are constituted to begin with by a variety of compositional principles, thus yielding varying qualities of association. Together these principles of association form “a kind of Attraction, which in the mental world will be found to have as extraordinary effects as in the natural, and to shew itself in as many and as various forms” (12–13).
Such privileging of sensible, affective, and compositional dimensions informs Hume’s discussion of time in Book I of the Treatise. Hume argues “that time cannot make its appearance to the mind, either alone, or attended with a steady unchangeable object, but is always discover’d by some perceivable succession of changeable objects” (35). But Hume directly recognizes that attention to such succession of perceptions yields notions not only of quantity, but also of quality. Hume defines “the idea of time” (34) as “an abstract idea, which comprehends a still greater variety than that of space, and yet is represented in the fancy by some particular individual idea of a determinate quantity and quality” (35). Qualities of duration arise because, according to Hume, our idea of time is “deriv’d from the succession of our perceptions of every kind, ideas as well as impressions, and impressions of reflection as well as of sensation” (34–35), thus including “internal impressions,” which he specifies as “our passions, emotions, desires and aversions” (33) and which he has earlier excluded from our idea of space. Moreover, Hume emphasizes that each and every one of the impressions and ideas that combine into our sense of time constitutes a substantial experience: “’Tis certain then, that time, as it exists, must be compos’d of indivisible moments” (31) that “must be fill’d with some real object or existence” (39), which he also calls “sensible qualities” (39). He does not count these “indivisible moments” as supporting our sense of time; following Locke’s explicit argument, only succession does this job for Hume. Yet he devotes much of his discussion to the experiential endurance of these units, highlighting their positivity. Hume defines the moment in Book I of the Treatise as, strictly speaking, not a part of time; and yet, he also attributes to it what Gilles Deleuze identifies in Hume’s philosophy as “real existence.” As Deleuze explains it, “real existence” is “neither a mathematical nor a physical point, but rather a sensible one,” and he adds, “a physical point is already extended and divisible; a mathematical point is nothing.” A sensible point is indivisible, and yet it is something.11
Beyond highlighting the moment as a part of endurance by virtue of its “sensible qualities,” Hume argues that our
