OCCASIONALISM. - A philosophical movement that develops Cartesian philosophy by resolving its dualism by attributing efficient causality solely to God and merely occasional causality to finite beings.
Cartesians faced the grave problem of justifying and explaining the relationship between two substances (res cogitans and res extensa) that were not only distinct but entirely heterogeneous to one another, since extension is subject to rigorous mechanical causality while thought subsists independently of the corporeal world. Descartes had merely accepted the correspondence between physical and psychical events empirically; his successors felt compelled to provide a philosophical foundation. Hobbes, Spinoza, and Leibniz resolved the dualism respectively through naturalistic mechanism, absolute monism, and spiritualistic pluralism, thus departing from Cartesianism. The occasionalists, however, sought to resolve the problem in a metaphysical-religious sense, firmly maintaining—and indeed accentuating—the Cartesian distinction between substances.
In the work *Corporis et animae in homine coniunctio* by J. Clauberg, any direct connection between body and soul is denied. According to Platonic tradition, the most perfect ideas are of things, and since a cause cannot be inferior to its effect, bodily motions are, in the Stoic terminology used by Clauberg, *causae procaracticae*, in that they merely provide the “occasion” for the manifestation of ideas that the mind always possesses virtually within itself. L. de la Forge denies not only the possibility of reciprocal influence between soul and body but also the action of one body upon another, noting that the clear and distinct idea of corporeity—i.e., according to Cartesian doctrine, of extension—does not imply the property of motive force. The movements of a body and the volitions of an individual spirit are merely *causae occasionales* of other movements because the principal motive cause, God, acts upon bodies according to the laws of motion and accommodates the wills of spirits within the limits of the freedom He has granted them. Similarly, for G. de Cordemoy, the nature of finite substances does not necessarily entail the relation of cause and effect, while all depend upon the free causality of God.
The first doctrinal formulation of occasionalism is due to A. Geulincx, who, like Descartes, begins from self-consciousness, noting that it does not imply knowledge of how the thinking I can determine the movements of its own body or act upon external bodies, nor how representations independent of human will arise in the mind. On the principle that one cannot act without clear consciousness of the action (“*quod nesciis quomodo fiat, id non facis*”), he concludes that man is merely a spectator, not an agent, of those manifestations whose origin he does not clearly know. It is therefore necessary to attribute causality to another spiritual substance (since *influxus physicus* is excluded) endowed with conscious will; this can only be God. Bodies thus become instruments of divine causality. Initially, Geulincx, like most occasionalists, admitted that God intervened through a series of distinct acts to determine each individual relation between spiritual and corporeal substance. However, faced with the difficulties that arose from this position—particularly regarding sin, which could not be attributed to a direct and specific intervention of God—Geulincx attributed the coincidence of physical and psychical events to the preordaining wisdom of God, resorting to the well-known analogy of two clocks that keep perfect time without causal interaction, their synchrony being due to an initial agreement conferred by the maker.
By depriving individual corporeal and spiritual beings of any faculty of action, Geulincx tended to deny their substantiality as well, considering bodies as modes of a single extended substance and spirits as modes of the divine Spirit. Occasionalism thus assumed a decisively mystical character, which is especially evident in the ethics of A. Geulincx: the highest virtue is humility, attained through self-knowledge (“*inspicio et despicio sui*”); moral life is pure interiority, complete dedication to God, since every relation with the external world is illusory and devoid of value (“*ubi nihil vales, ibi nil velis*”).
Regarding knowledge, Geulincx criticizes the Aristotelian-Scholastic realism of gnoseology, affirming that things, as they are in themselves, remain inaccessible to human understanding. Occasionalist gnoseology is developed by the foremost representative of occasionalism, N. Malebranche, in his principal work *De la recherche de la vérité* (1675). Malebranche too accentuates Cartesian dualism, denying the possibility of reciprocal influence between spiritual and corporeal beings and indeed any form of autonomous activity in finite beings; God acts directly upon them without employing any instrument. On this basis, the problem of knowledge is framed. True knowledge consists in the clear perception of ideas by the intellect, independently of sensations and passions, which are the principal sources of error. The fundamental problem thus concerns the origin of ideas; they cannot come from external objects because of the incommunicability between spirit and matter, nor can they be produced by the soul, which lacks creativity, nor be innate, since a finite spirit could not contain infinity. They can therefore be conceived only as thoughts in God, and knowledge is rendered possible only by 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 thus no inclination or aspiration of the human soul that is not ultimately love of God, even if it is misunderstood through sensory error and the arbitrariness of the will.
Malebranche admits human freedom, but as a mystery. Even the knowledge of God and self-consciousness (in contrast to Cartesian rationalism) have a mystical character: God cannot be known through clear and distinct ideas, though He is the first object of thought; self-consciousness has an intuitive value and coincides with the consciousness of participation in the Divinity. Only physical-mathematical knowledge is purely rational, referring to the clear and distinct idea of extension, but even this is possible only because God acts in the physical world through the simplest means, according to universal laws that remain constant despite changes in natural (occasional) causes. Rational speculation thus coincides with religious life.
Many Cartesians adhered to Malebranche’s occasionalism, including F. Lamy, a Benedictine monk; R. Fédé, a mathematician and physicist; the Jesuit P. André, a disciple of Malebranche and a staunch defender of his doctrine; and in Italy, M. Fardella. Occasionalism provoked fierce polemics in contemporary philosophical and religious circles. Above all, the Cartesians of Port-Royal opposed Malebranche’s doctrines, leading to a long dispute with Arnauld over the *Traité de la nature et de la grâce*.
recent bibliography in G. A. De Brie, *Bibl. philosophica* 1934–45, I, Brussels 1950, pp. 365–67. M. Elena Reina