OCCASIONALISM. — A philosophical current that develops dualism (v.) through attributing efficient causality solely to God, and to finite beings a purely “occasional” causality.
For the successors of Descartes, there arose the grave problem of justifying and explaining the relationship between two substances (the res cogitans and the res extensa) that were not merely distinct but entirely heterogeneous from one another, extension being subject to a rigorous mechanical causality, while thought subsisted in itself, independently of the corporeal world. Descartes had limited himself to accepting empirically the correspondence between physical and psychic events; his successors found themselves compelled by the need to provide it with a philosophical foundation. HOBBES, THOMAS (v.), Spinoza (v.) Leibniz (v.) resolve dualism respectively into a naturalistic mechanism, an absolute monism and a spiritualistic pluralism, thereby moving beyond the sphere of Cartesianism. The occasionalists, on the other hand, sought to resolve the problem in a metaphysical-religious sense, maintaining, indeed accentuating, the Cartesian distinction between substances. In J. Clauberg’s (v.) work Corporis et animae in homine coniunctio, every direct connection between body and soul is denied; since, according to the Platonic tradition, ideas are more perfect than things, and since the cause cannot be inferior to the effect, the movements of the body are, in the Stoic terminology used by Clauberg, causae procatarcticae, insofar as they provide only the “occasion” for the manifestation of ideas, which the spirit always possesses potentially within itself. L. la Forge (v.) denies not only the possibility of a reciprocal influence between soul and body, but also the action of one body upon another, pointing out that the clear and distinct idea of corporeity—that is, according to Cartesian doctrine, of extension—does not imply the property of motive force; the movements of one body and the volitions of an individual spirit are causae occasionales of other movements only because the principal motive cause, God, acts upon bodies according to the laws of motion and accommodates himself to the wills of spirits, within the limits of the freedom he has granted them. Similarly, according to G. Cordemoy (v.), the relation of cause and effect does not necessarily belong to the nature of finite substances, whereas all of them depend upon divine free causality.
The first doctrinal formulation of occasionalism is owed to A. GEULINCX, ARNOLD (v.); like Descartes, he begins from self-consciousness, observing that it does not entail knowledge of how the thinking self can determine the movements of its own body or act upon external bodies, nor of how representations independent of the human will are formed in the mind. On the basis of the principle that one cannot act without having clear consciousness of one’s action (“quod nescia quomodo fiat, id non facia”), he concludes that man is merely a spectator, not the actor, of those manifestations whose origin he does not clearly know. Their cause must therefore be attributed to another spiritual substance (since influens physicus is excluded) endowed with conscious will; this can only be God: bodies thus become instruments of divine causality. At first Geulincx admitted, like most of the occasionalists, that God intervened through a series of distinct acts to determine the individual relations between spiritual substance and corporeal substance. But, faced with the difficulties arising from this position, particularly with regard to sin, which could not be attributed to a direct and specific intervention by God, Geulincx attributed the coincidence of physical facts with psychic ones to God’s preordaining wisdom, resorting to the familiar comparison of the two clocks, which function in perfect synchrony without standing in a reciprocal causal relationship, but through an agreement initially imparted to them by their maker. By removing every capacity for action from individual corporeal and spiritual beings, Geulincx also tends to deny their substantiality, considering bodies as modes of a single extended substance and spirits as modes of the divine Spirit. Occasionalism thus assumes a decidedly mystical character, and this is especially evident in the ethics of A. Geulincx: humility is regarded as the highest virtue, attained through self-knowledge (“inspectio et despectio sui”); the moral life is pure inwardness, complete devotion to God, since every relationship with the external world is illusory and devoid of value (“ubi nil vales, ibi nil velis”). With regard to knowledge, Geulincx criticizes the epistemology of Aristotelian-scholastic realism, asserting that things as they are in themselves remain unknowable to human beings. Occasionalist epistemology is developed further by the foremost representative of occasionalism, N. Malebranche (v.), in his principal work De la recherche de la vérité (1675). Malebranche likewise accentuates Cartesian dualism, denying the possibility of a reciprocal influence between spiritual and corporeal beings, and indeed any form whatsoever of autonomous activity in finite beings; God acts directly upon them, without employing any instrument. On this basis, the problem of knowledge is formulated. True knowledge consists in the intellect’s clear perception of ideas, independently of sensations and passions, which are the principal sources of error. The fundamental problem therefore concerns the origin of ideas; they cannot derive from external objects, because of the incommunicability between spirit and matter, nor be produced by the soul, which lacks creativity, nor be innate, since the finite spirit could not contain their infinity. They can therefore be conceived only as present in God, and knowledge is made possible only through a direct relation of participation with the divine mind. Just as finite bodies are in space, so finite spirits are in God, who is “the place of spirits.” There is therefore no inclination or aspiration of the human soul that is not, ultimately, love of God, even if it is misunderstood through an error of the senses and an arbitrary act of the will. Malebranche does in fact admit freedom in man, but as a mystery. Knowledge of God and self-consciousness (in contrast with Cartesian rationalism) likewise have a mystical character: one cannot have a clear and distinct idea of God, although God is the first object of thought; self-consciousness (v.) has an intuitive value and coincides with consciousness of participation in the Divinity. Only knowledge of a physical-mathematical kind is purely rational, since it refers to the clear and distinct idea of extension; but such knowledge is possible only because God acts in the physical world by the simplest means, according to universal laws that remain constant as natural (occasional) causes vary. Rational speculation therefore once again coincides with religious life.
There were numerous Cartesians who became followers of Malebranche’s occasionalism; among them were F. Lamy, a Benedictine monk; R. Fedè, a mathematician and physicist; the Jesuit Father P. André, a disciple of Malebranche and a staunch defender of his doctrine; and, in Italy, M. Fardella. Occasionalism aroused serious controversies in the philosophical and religious circles of the time. The Cartesians of Port-Royal in particular opposed Malebranche’s doctrines, and he was obliged to engage ARNALDISTI (v.) concerning the Traité de la nature et de la grâce.