From Universal Mathematics to Universal Method: Descartes's "Turn" in Rule IV of the Regulae

From Universal Mathematics to Universal Method: Descartes's "Turn" in Rule IV of the Regulae PAMELA A. KRAUS I. THE QUESTION OF THE REGULAE DESCARTES'SFIRSTPHILOSOPHICAL TEXT, Regulae ad directionem ingenii,' is also the first formulation of his notion that philosophizing must begin by elaboration of the true method. Many scholars, however, have regarded the Discours de la m~thode as the primary text for the study of Cartesian method. The Discours, unlike the Regulae, is a complete and published writing, and its succinct statement of the "four rules of method" has attained something of a canonical status. Yet the Discours is clearly a popular writing, intended as an introduction to the appended scientific Essais; '~ and its individual rules are ' The importance of the text was immediately recognized by seventeenth century thinkers. Baillet calls it a model for "an excellent logic," Adrien Baillet, La vie de Monsieur Descartes (Paris: 1691), T. I, p. 282. Parts of Rules XIII and XIV were used for the second edition of the Port Royal Logic, Antoine Arnauld and Charles Savreux (1664). Leibniz procured and annotated his own copy. Leibniz's manuscript was found during the later half of the nineteenth century and was published in Oeuvres inedit~s de Descartes, ed. M. Le Cte. Foucher de Careil (Paris: A. Durand, 1859-6o ). The appropriate extracts of these, as well as the text of the Regulae can be found in Oeuvres de Descartes, eds. Charles Adam and Paul Tannery, vnl. l() (Paris: J. Vrin, 1966 ). (Hereafter abbreviated AT.) This version was unsurpassed until recently. In 1965, Giovanni Crapulli published an edition which uses all the available manuscript sources (AT uses the 17~ | Latin edition and Leibniz's "Hanover" manuscript only): Regulae ad directionem ingenii, ed. Giovanni Crapulli (The Hague: Martinus Nijhoff, 1963). We will follow the English translation of Haldane and Ross (hereafter abbreviated HR), which is based on AT. Rules for the Direction ~f the Mind, in Philosophical Works of Descartes, trans. Elizabeth S. Haldane and G.R.T. Ross, V. I (Cambridge at the University Press, 1979), pp. 1-77. The textual challenge was formulated on the basis of AT, and the reply to this challenge made by Jean-Luc Marion, which we shall also consider, does not require Crapulli. "Mon dessein n'a point 6t6 d'enseigner toute ma M~thode dans le discours o/~ je la propose, mais seulement d'en dire assez pour faire juger que [es nouvelles opinions, que se verraient dans la Dioptrique, et dans les M6t6reos, n'etaient point conques ~ la 16g~re, et qu'elles valaient peut-~tre la peine d'etre examin6es," Au Vatier, 'a2 f6v. 1638. AT ~:559 1. 13ff. [~59] 160 HISTORY OF PHILOSOPHY never explained in themselves or in their sequence. It is customary then to supplement the Discours with the Reg~ulaewhich is a treatise that has method as its sole subject? Even if the four rules of the Discours are the same in meaning as certain rules in the Regulae, as Gilson suggested, only the latter text has paragraphs and often pages which explain them and show their ['unction. It alone connects method with the operations of the diverse faculties of knowledge, intellect, imagination, and sensation, and shows how their objects relate to the world. Of all the Cartesian writings, only the Regulae shows how method can found a science of the world. Accordingly, the Regulae has increasingly commanded attention in its own right as an autonomous source of Cartesian thought and not merely as auxiliary to later Cartesian texts. The weight we should assign to the Regulae is suggested by Heidegger: "Only one who has really thought through this relentlessly sober volume long enough, down to its remotest and coldest corner, I'ulfills the prerequisite for getting an inkling of what is going on in modern science. ''4 It is often thought that the primacy of metaphysics in the Meditationes supersedes the primacy of method in the Regulae and the Discours.5 It is :~ Gilson notes that the Regulae and the Discours are in basic agreement: ("... les deux nuvrages cciir/cident pour le fond"), but he maintains that the Regulae does not contain supplementary precepts, only more rules [or...