The French philosopher and theologian Nicolas Malebranche (1638-1715) was a noted Cartesian. His analysis of the fundamental presuppositions of Descartes's philosophy led to a set of doctrines that is known as occasionalism.
Born in Paris, Nicolas Malebranche was educated at the Collège de la Marche and at the Sorbonne. In 1660 he entered the Oratorian order, which had been founded by Cardinal Pierre de Bérulle, an early supporter of René Descartes. Sometime after his ordination in 1664, Malebranche chanced upon a copy of Descartes's On Man. This incomplete treatise was an attempt to explain man's physiology as part of a system of universal mechanics. On the strength of this work, Malebranche devoted the next 10 years of his life to the study of science and of Descartes's philosophy.
Occasionalism is a theory of causal interaction. Descartes's metaphysics culminates in an extreme dualism according to which matter and mind are totally independent substances. The observable connections between mind and body were a fact that Descartes bequeathed to his successors for explanation. The first recourse was to a deus ex machina: God alone accounts for the interaction. A Dutch thinker, Arnold Geulincx, offered the first coherent theory with his analogy that physical actions and mental volitions are like two clocks that are synchronized by God so that they keep time together.
The culmination of occasionalism and of Malebranche's study is found in his major work, The Search for Truth, the first volume in 1674 and the second in 1675. Although occasionalism, as explained above, is positive as a possible explanation, it is even more interesting in its negative connotations, since the theory means that despite appearances there is no real interaction between spirit and matter. Spirit is understanding and will, and matter is figure and motion. Malebranche stresses not only that these parallel attributes are mutually exclusive but also that both mind and matter, in themselves, have no power or activity. Hence there is no secondary causality, and God is the only real cause of ideas and motions in the universe.
The consequences of this view are most important with regard to the theory of knowledge. The mind has a disposition to receive ideas, and on the occasion of sensory impressions or movements the appropriate idea arises in consciousness. The originals of such ideas, following the Platonic, Augustinian tradition, are archetypes of the divine mind according to which all things have been created. Thus the reason a finite mind can possess infinite, eternal truth is that it has been illuminated to "see all things in God." The full implications of such a doctrine were left by Malebranche as future problems: reality consists of ideas; our experience of objects is, at best, deceptive; what reality the material world possesses other than ideal is open to question. To underscore these contentions, Malebranche offered several criticisms and arguments to prove that neither reason nor experience can discover any necessary connections between two events that we relate as cause and effect. Ironically these arguments were taken over, practically verbatim, by the Scottish philosopher David Hume in support of his skeptical empiricism.
The success of The Search for Truth was considerable. Opposed by other Cartesians and theologians, Malebranche spent much of the remainder of his career defending himself in print. His other major works are Christian Conversations (1675), Treatise on Nature and Grace (1680), Treatise of Morality (1683), and Dialogues on Metaphysics and on Religion (1688). His scientific work in geometry and physics was respectable, and in 1699 he was honored by election to the French Royal Academy of Sciences.
Further Reading on Nicolas Malebranche
A work of Malebranche available in English is Dialogues on Metaphysics and on Religion, translated by Morris Ginsberg (1923); it contains a long introduction to Malebranche's life and thought by the translator. The secondary material on Malebranche includes Ralph W. Church, A Study in the Philosophy of Malebranche (1931); A. A. Luce, Berkeley and Malebranche: A Study in the Origins of Berkeley's Thought (1934); and Beatrice K. Rome, The Philosophy of Malebranche: A Study of His Integration of Faith, Reason and Experimental Observation (1963).
Additional Biography Sources
Nadler, Steven M., Malebranche and ideas, New York: Oxford University Press, 1992.
Chappell, V. C. (Vere Claiborne), Nicholas Malebranche, New York: Garland, 1992.