Justifying Descartes' Causal Principle

Abstract

Justifying Descartes' Causal Principle LOIS FRANKEL IT IS WELL KNOWN that Descartes is committed to some principle of causation . That commitment has subjected him to frequent criticism along the following lines: It seems that Descartes uses a causal principle (among other "clear and distinct" principles) as a premise in a proof of God's existence and veracity, and then turns around and validates clear and distinct perception by means of that proof. This classic difficulty, a version of the 'Cartesian Circle', has inspired many defenses. I find the most useful strategy to be one which shows how the premises of the Third Meditation proof of God's existence, including, notably, various causal principles, are unaffected by the deceiver hypothesis, and thus immune even to metaphysical doubt, and so exempt from any need of a divine guarantee.' Defenses of this sort lead to the further question: What is Descartes' reason or justification for taking causal principles to the among those immune to the deceiver? My purpose will be to show that Descartes' commitment to causal principles is part of his commitment to rational explanation, and thus that he is as entitled to the principle as to any other foundation of his system. The citations for each quotation in this paper refer first to a description or tide of the work, when applicable, then to the English translation used, and finally to the original-language source, which appears in parentheses. The following abbreviations are used: AG: Elizabeth Anscombe and Peter Thomas Geach, trans., Descartes:Philosophical Writings (New York: Bobbs-Merrill, 1954). AT: Charles Adam and Paul Tannery, eds. Oeuvresde Descartes(Paris: Cerf, 1897-1913). HR: Elizabeth S. Haldane and G. R. T. Ross, trans., The Philosophical Works of Descartes (Cambridge: Cambridge University Press, 1931), 2 vols. K: Anthony Kenny, ed. and trans., Descartes'PhilosophicaILetters(Oxford: Oxford University Press, 197o). ' I discuss some of these points in my paper, "Reason and Antecedent Doubt," Seuthern Journal of Philosophy 22:3 (Fall 1984). [323] 324 JOURNAL OF THE HISTORY OF PHILOSOPHY 2423 JULY 1986 1. TO set the stage for this discussion, I would like to comment on four separate causal principles (which can, alternatively, be thought of as versions of a single principle) to be found in Descartes' writings. The various causal principles appear in different contexts, and serve different purposes; two of them appear as explicit premises of the Third Meditation argument for the existence of God, and are the causal principles most central to the current inquiry: (C~) The efficient and total cause of an effect must have at least as much reality as the effect. (C,) The cause of an idea must have at least as much formal reality as the idea has objective reality. Descartes considers both of these to be first principles, true by the 'light of nature"; (C,) is in at least one place treated as "identical" (i.e., logically equivalent) to the well-known and common principle, (Cs) Nothing is not the cause of any being or effect (ax n/h//o nihilfit). That there is nothing in the effect, that has not existed in a similar or in some higher form in the cause, is a first principle than which none clearer can be entertained. The common truth 'from nothing, nothing comes' is identical with it. For, if we allow that there is something in the effect which did not exist in the cause, we must gram also that this something has been created by nothing; again the only reason why nothing cannot be the cause of a thing, is that in such a cause there would not be the same thing as existed in the effect, s (Cs) also is a first principle, an 'eternal truth', 'manifest by the natural light', an 'axiom' and a 'common notion'? Finally, at the most basic level, the causal principle may be stated as follows: (C4) Everything which exists has a cause. This version of the principle is never mentioned explicitly in the Meditat /0r,s, even though it is presupposed by the variations previously discussed. Rather, it appears in the Replies: But it seems to me to be self-evident that everything that exists springs either from a...