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

Abstract

Hume's First Principle, 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 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