In lieu of an abstract, here is a brief excerpt of the content:Hume Studies Volume 29, Number 1, April 2003, pp. 29-41 Hume's Argument for the Temporal Priority of Causes TODD RYAN In a section entitled "Of Probability; and of the idea of cause and effect," Hume embarks on a search for the conceptual components of our idea of causation. Rejecting the possibility of analyzing the idea in terms of the qualities of objects, Hume claims to discover two constituent relations. (...) First, a cause and effect must be contiguous in space and time because "nothing can operate in a time or place, which is ever so little remov'd from those of its existence" (T 1.3.2.6; SBN 75).x Second, a cause must be temporally prior to its effect. Although experience is said to confirm this latter requirement "in most instances," Hume goes on to present an argument purporting to demonstrate that the temporal priority of a cause is an essential feature of every instance of causation.2 Despite the extensive treatment that his analysis of causation has occasioned, Hume's argument for the temporal priority of causes has received comparatively little attention. In this paper I hope to remedy this neglect by providing a more accurate explication of the argument than has previously been offered. Hume does not argue directly for the claim that a cause must be temporally prior to its effect. Rather he offers an alleged reductio ad absurdum of the opposing view that "'tis not absolutely necessary a cause shou'd precede its effect; but that any object or action, in the very first moment of its existence, may exert its productive quality, and give rise to another object or action, perfectly co-temporary with itself (T 1.3.2.7; SBN 76)." This careful summary Todd Ryan is Assistant Professor of Philosophy, Trinity College, Hartford, CT 06106-3100, USA. e-mail: [email protected] 30 Todd Ryan of the opposing view provides a clear statement of what Hume takes to be at issue, namely whether it is "absolutely necessary" that a cause be temporally prior to its effect. From this it can readily be inferred precisely what would count as a refutation of his own view. Specifically, if it could be shown that some objects can produce their effect perfectly contemporaneously with themselves, then his position would have to be abandoned.3 It is against this latter possibility that Hume directs his argument. He writes: 'Tis an establish'd maxim both in natural and moral philosophy, that an object, which exists for any time in its full perfection without producing another, is not its sole cause; but is assisted by some other principle, which pushes it from its state of inactivity, and makes it exert that energy, of which it was secretly possest. Now if any cause may be perfectly co-temporary with its effect, 'tis certain, according to this maxim, that they must all of them be so; since any one of them, which retards its operation for a single moment, exerts not itself at that very individual time, in which it might have operated; and therefore is no proper cause. The consequence of this wou'd be no less than the destruction of that succession of causes, which we observe in the world; and indeed, the utter annihilation of time. For if one cause were co-temporary with its effect, and this effect with its effect, and so on, 'tis plain there wou'd be no such thing as succession, and all objects must be co-existent (T 1.3.2.7; SBN 76). The general structure of the argument is reasonably clear. According to the "establish'd maxim" (hereafter EM) any object that does not produce an effect as soon as possible is not the "sole cause" of that effect. Assuming then that causes might occur simultaneously with their effects, it follows that every proper cause must be contemporaneous with its effect. But if every effect occurs simultaneously with its cause, then we arrive at the absurd conclusion that there can be no causal (or indeed temporal) succession in the world. Therefore, the original assumption that a cause may be perfectly co-temporary with its effect must be... (shrink)

Shepherd propounds a theory of mind with a fair claim to be better than Hume’s at explaining the sources of commonly held human beliefs about causal necessity due largely to her relational theory of sense perception. In comparison with Hume’s account, it incorporates a more sophisticated treatment of mental representation, especially the role of relational structure and logical form. Most important, perhaps, Shepherd’s theory enforces the division, obscured by Hume, between the evidence of necessity and the metaphysical foundation of necessity.