The Breakdown of Cartesian Metaphysics

The Breakdown of C i M phy " artes an eta sacs RICHARD A. WATSON WITHIN CARTESIANISMthere arose many problems deriving from conflicts between Cartesian principles. Inadequate attempts to solve these problems were crucial reasons for the breakdown of Cartesian metaphysics in the late seventeenth and early eighteenth centuries. The major difficulties derived from the acceptance of a dualism of substances seated in a system which included epistemological and causal likeness principles plus an ontological framework in which the categories of substance and modification were exhaustive . The major solutions involved either denying the likeness principles or altering the ontological framework. The first led to unintelligibility ; the second, culminating in Hume, opened the way to non-Cartesian metaphysics. The first section of this study contains a characterization of late seventeenth -century Cartesian metaphysics. The second is an exposition of Foucher 's four major criticisms of this system. In the third section, monistic solutions suggested in Descartes and by Spinoza, Foucher, Leibniz, and Locke are considered; in the fourth, the dualistic solutions of the orthodox Cartesians Rohault, R~gis, Desgabets, La Forge, Le Grand, and Arnauld; and in the fifth, the occasionalist solution of Malebranche. The sixth section is an analysis of these orthodox and occasionalist solutions, showing how each ultimately fails because of dependence upon the ontology of substance and modification. The seventh section is a consideration of Berkeley and Hume in the Cartesian context. A consideration of their systems as offering solutions to Cartesian problems illuminates in new light both the systems and the problems. In broad terms, this study moves from a consideration of problems arising from an ontology of two substances, to a consideration of problems arising from the ontological pattern of substance and modification. The Cartesians were concerned with relationships between two substances, but they saw no difficulties connected with the relationship between a substance and its modifications (or properties). Berkeley's treatment (deriving from Male- [177] 178 HISTORY OF PHILOSOPHY branche) of the relationships between mind and idea, and between mind and notion, is illuminated by a consideration of the extent to which he took these relationships for granted in the Cartesian way, and of the extent to which he saw difficulties in the relationship between substance and modification . The Berkeleian solution to Cartesian problems, like that of Malebranche before him, was not successful; Malebranche belittled, and Berkeley denied the dualism of substances, but neither philosopher could break entirely with the ontological pattern of substance and modification. The final breakdown of Cartesian metaphysics came with Hume, who, in providing the culmination of a most important trend in modern philosophy, opened the way to new metaphysics and became the father of contemporary philosophy. I A model late seventeenth-century Cartesian metaphysical system. The last grand expositor of the Cartesian philosophy was Antoine Le Grand who in 1694 published An Entire Body of Philosophy. The characterization of the late seventeenth-century Cartesian system given below follows Le Grand's exposition more closely than others, but it also incorporates elements from those of Rohault, R6gis, Desgabets, La Forge, Malebranche, and Arnauld.1 None of these philosophers professed a system of exactly the sort this characterization pictures, nor is it implied here that they do. The guide and rationale for drawing from them such a model Cartesianism is the polemical writing of Simon Foucher. Foucher's series of attacks upon Cartesianism (of which the second is his criticism of Malebranche of 1675, Critique de la Rdcherche de la veritd) give clearly the most important objections against Cartesian metaphysics.2The system outlined below, while more com1Le Grand, Antoine, An Entire Body of Philosophy According to the Principles of the Famous Renate des Cartes (London, 1694); Rohault, Jacques, Traitd de physique (Paris, 1671); R6gis, Pierre-Sylvain, Syst~me de philosophie, contenant la logique, la mdtaphysique, la physique et la morale (Lyon, 1690); Desgabets, Robert, Critique de la Critique de la Recherche de la veritd, oCt l'on decouvre le chemin qui conduit aux connoissances solides. Pour servir de rdsponse gtla Lettre d'un academicien (Paris, 1675); La Forge, Louis de, Traitd de l'dme humaine, de ses facultds et fonctions et de son union avec le corps, d'apr~s les principes de...