Routledge History of Philosophy Volume IV

322 RENAISSANCE AND SEVENTEENTH-CENTURY RATIONALISM
substances have any causal efficacy whatever. In complete occasionalism, no
creature has the power to bring any mode into existence, either in itself or in
another thing. All modes are produced directly by God on the occasion of certain
creatures being in certain states.
Who was the first Cartesian philosopher to advocate occasionalism? Descartes
himself sometimes uses the word ‘occasion’ to describe the body’s action on the
soul. For example, he writes in the Treatise on Man that, when the nerve fibres
are pulled with a force great enough to separate them from the parts to which
they are attached, they ‘cause a movement in the brain which gives occasion for
the soul…to have the sensation of pain’. 9 Descartes ought not on this account to
be taken for an occasionalist, however. He does not assert that God produces the
sensation on the occasion of the body’s motion, but only that the motion gives
occasion for the soul to have the sensation. There is no textual evidence that he
tied the notion of giving occasion to a denial of causal efficacy. As Gouhier
observes, for Descartes ‘occasion’ is a word of ordinary language rather than a
substitute for the word ‘cause’. 10
There are hints of occasionalism in the work of the German Cartesian
philosopher Johannes Clauberg (1622–65). In De corporis et animae in homine
conjunctione, published in 1664, Clauberg argues that since the effect cannot be
nobler than the cause the movements of the body are only procatarctic causes,
which give occasion to the mind as principal cause to elicit ideas that are
potentially in it. He also claims that the soul does not produce movement in the
body but only directs it as a coachman directs a carriage. Nevertheless, the key
element of occasionalism, the assignment of causal efficacy to God in specific
instances, is missing in his writings. 11
Occasionalism has three originators: Louis de La Forge (1632–66); Géraud de
Cordemoy (1626–84); and Arnold Geulincx (1624–69). La Forge was the first
Cartesian to use the term ‘occasional cause’. 12 His Traitté de l’esprit de l’homme
appeared at the end of 1665, although it carries the publication date of 1666.
According to a contemporary, Jacques Gousset, La Forge disclosed his
occasionalist opinion about 1658. 13 Cordemoy’s Discernement du corps et de
l’âme was published in 1666. At the beginning of the Fifth Discourse, on the
union of the mind and the body and how they act on each other, he remarks that
he told some friends about his ideas seven or eight years earlier. Battail takes this
as evidence that Cordemoy’s occasionalism was already mature in 1658 or
1659. 14 Thus La Forge and Cordemoy developed and published their
occasionalist views at the same time. It is possible that there was communication
between these two philosophers. 15 But there is no evidence of any actual meeting. 16
Neither author refers to the other. According to the editor of Clauberg’s Opera,
Clauberg corresponded with La Forge. 17 La Forge refers to Clauberg in the
Traitté, but not in reference to occasionalism.
Geulincx’s occasionalism is in the Ethica, the first part of which was
published in 1665, and in the Metaphysica vera, published posthumously in 1691.
There is no evidence of influence in either direction between Geulincx on the