Hume's First Principle, His Missing Shade, and His Distinctions of Reason

Hume Studies Volume XXII, Number 1, April 1996, pp. 105-121 Hume's First Principle, His Missing Shade, and His Distinctions of Reason KARANN DURLAND I. The Puzzle Hume's First Principle, "all our simple ideas in their first appearance are deriv'd from simple impressions, which are correspondent to them, and which they exactly represent," is not only the fundamental principle of his theory of mind; it is also his criterion of significance.1 Given that all ideas can ultimately be traced to preceding simple impressions which they exactly resemble , to understand an idea, Hume claims, we must examine its corresponding impression (or, if the idea is complex, analyze it into its simple components and examine their corresponding impressions). To show that some putative idea is a fiction, we need only show that we lack the corresponding impression(s). Hume employs the Principle as his criterion of significance when he argues that we have no idea of necessary connection (as a quality of bodies), of substance, or of the (simple) self, among other things. Quick work could be made of both Hume's psychology and these attacks on our ideas if a counterexample to his Principle could be found. Curiously and infamously, after arguing on behalf of the Principle, emphasizing its importance, and even challenging us to find a counterexample, he introduces "one contradictory phaenomenon, which may prove, that 'tis not absolutely impossible for ideas to go before their correspondent impressions" (T 5).2 He says, Suppose...a person to have enjoyed his sight for thirty years, and to have become perfectly well acquainted with colours of all kinds, Karánn Durland is at the Philosophy Department, University of North Carolina at Chapel Hill, CB# 3125, Caldwell Hall, Chapel Hill, North Carolina, 27599-3125 USA. email: kdurland@email.unc.edu. 106 Karánn Durland excepting one particular shade of blue, for instance, which it has never been his fortune to meet with. Let all the different shades of that colour, except that single one, be plac'd before him, descending gradually from the deepest to the lightest; 'tis plain that he will perceive a blank, where that shade is wanting, and will be sensible, that there is a greater distance in that place betwixt the contiguous colours , than in any other. Now I ask, whether 'tis possible for him, from his own imagination, to supply this deficiency, and raise up to himself the idea of that particular shade, tho' it had never been conveyed to him by his senses? I believe there are few but will be of opinion that he can; and this may serve as proof, that the simple ideas are not always derived from the correspondent impressions. (T 6) This concession and Hume's subsequent treatment of the phenomenon are puzzling. If the phenomenon is a counterexample to the First Principle, then the Principle, and all that rests on it, ought to be abandoned. Yet Hume instead dismisses the phenomenon and does so with hardly any explanation. Whether this dismissal is legitimate has concerned readers ever since. Some say the exception is illusory, that Hume grants only the possibility of an exception (not that one exists), that the idea does not appear before its corresponding impression after all, or that although the idea does precede its impression, it is complex rather than simple. I maintain that the phenomenon is a genuine and important exception to the Principle and argue that Hume can nonetheless deploy the Principle as both his fundamental psychological thesis and his criterion of significance. If 1 am right, the Principle can be upheld despite its admitting exceptions because Hume's distinctions of reason can account for the exceptions in a way that does not undermine his use of the Principle.3 II. Some Unsatisfactory Proposals I assume that two conditions must be met to explain why Hume can (or at least reasonably thought he could) discard the phenomenon. First, the fact that the phenomenon is contradictory (and contradictory in the sense he claims) must be preserved: The idea of the missing shade must be simple, and it must precede its corresponding impression.4 Second, the account must explain both why he can uphold...