Régis, Pierre-Sylvain (1632–1707)
Pierre-Sylvain Régis was a student of the Cartesian physicist Jacques Rohault. Like Rohault, Régis expounded Cartesianism in public lectures. In 1680 François de Harlay de Champvallon, the archbishop of Paris, told Régis that King Louis XIV forbad public lectures for fear of uproar concerning the Cartesian explanation of transubstantiation. Régis continued to give private lessons, and by 1699 the conflict over Cartesianism had subsided, leading to his admission to the Academie des Sciences, along with Nicolas Malebranche, whose occasionalist philosophy was a response to problems of Cartesian dualism.
Régis's system is based on fourteen self-evident metaphysical principles derived from the cogito (Descartes' basic axiom: "I think, therefore I am").
(1) All properties belong to something, that is, nothing can have no properties
(2) All effects presuppose causes
(3) An effect can have no more perfection than does its total cause
(4) All changes in a subject proceed from an external cause
(5) All modes presuppose substances in which to exist
(6) A mode that modifies one kind of substance cannot modify any other kind of substance
(7) All that exists is either a substance or a mode
(8) Essences are indivisible; if anything is added to or subtracted from an essence, it is destroyed
(9) Privations and negations are known only by their opposites
(10) External things are known only by way of ideas; what one has no idea of is to one as though nonexistent
(11) All ideas, to the extent that they represent properties, depend on their objects as exemplary causes
(12) The exemplary cause of an idea contains formally all the perfections the idea represents
(13) Facts attested by many people of diverse times, nations, and interests as known in themselves and of which one cannot suspect conspiracy to support a lie should be accepted as constant and indubitable as though one had viewed them oneself
(14) Witness of infinitely powerful, wise, good, and truthful God should have as much persuasive force on one's mind as the most convincing reasons
The ontological principles are to the effect that whatever exists is either a substance or a modification of a substance and that modifications cannot belong to nothing. The basic epistemological principle is that external material bodies can be known only by way of representational ideas that are themselves mental modifications of the mind. The central principle is that all effects presuppose causes that must have as much or more perfection than their effects. All modifications are effects and thus are ultimately caused by a substance. All ideas (both sensory images and intelligible concepts) are also effects caused by some substance, and all of them represent the perfections of their causes. The basic problem with these assertions is that mind whose essence is active unextended thinking is essentially unlike matter whose essence is passive unthinking extension. Thus, all Cartesians must face the two questions first posed to René Descartes by Princess Elisabeth of Bohemia: Given that Cartesian mind and matter are essentially unlike one another, how can they interact causally? And how can a mind know extended matter by way of unextended sensations and ideas? Régis answers as Descartes does that one knows causal interaction takes place and God can make this happen, even if one does not understand how. The question of how mental ideas can represent material bodies that are essentially unlike mental things is also settled in the Cartesian way with the assertion that God makes it so, even if one does not understand how.
Régis maintains that his metaphysics, logic (which follows Antoine Arnauld's), and ethics (based on self-interest) are certain and complete. Physical explanations are also based on self-evident principles, but those humans give are only probable because, on the principles of Cartesian physics, several explanations are deducible for each event, and one does not know which one God chose. Régis says that the simplest is the most probable. If one had complete knowledge of the Cartesian deductive system as God does, however, one would have certain knowledge in physics, and one should keep that goal in mind. But the search must be made systematically. Régis, like Descartes, opposes "arbitrary hypotheses," explanations not deducible from self-evident principles within a system. Ad hoc explanations that are not part of a comprehensive theory are useless. Régis, like Descartes and all later Cartesians, believes the correct theory is mechanism.
The most distinctive feature of Régis's Cartesianism is his doctrine that man is a compound substance. In this union, eight conditions pertain:
(1) The soul always has the idea of extension
(2) Specific brain movements cause specific ideas
(3) Animal spirits cause motions in the brain that give rise to imagination, sensation, and memory of material objects
(4) Pleasure and pain are signs of bodies suitable and unsuitable to the human body
(5) Man has a penchant to love or hate, and pursue or flee, the objects of pleasurable or painful ideas
(6) Sentiments and passions lead to actions of the body toward self-preservation
(7) The soul thinks of particular bodies only when particular brain movements occur
(8) The union holds only so long as the body is alive and functions properly
Because ideas must have existing exemplary causes, Régis argues contrary to Descartes that one knows both the essence and existence of both mind and matter.
Man, Régis explains (as did Descartes' Dutch disciple Regius [Henry de Roy]), is an accidental union of mind or soul and body. Descartes himself adamantly opposes this view by insisting that the union is substantial, not accidental. If the union is only accidental, this makes the mind or soul a property of the body, not a substance on equal standing with the material substance. Then when the body dies, this accidental mind or soul would disintegrate with the other bodily properties. Régis argues that in fact the soul disintegrates and the mind survives, but it cannot think temporally—because this depends on bodily motions—and instead can contemplate only itself and God.
Like Descartes, Régis shows how operations of the body take place through actions of external bodies on sense organs to cause movements in the brain. He admits that causal interaction between mind and body is inexplicable and can be accepted only on faith. It is a brute fact that because of its union with a body, a mind or soul has the idea of extension and can cause that body to move. And because of the union, distinctive brain movements always give rise in the mind to distinctive sensations and concepts of the material objects affecting the brain.
Descartes asserts that one is born with innate ideas of mind, God, and matter. But Régis says that all ideas, even of God, depend on brain movements. Thus for Régis, after separation of mind and body at death, the mind no longer has the idea of extension, and no imagination or memory of, or power over, the material world.
Régis claims that Pierre-Daniel Huet thinks Descartes is a skeptic because Huet does not distinguish methodological from real doubt. Also, Huet is wrong to argue that Descartes' explanation of transubstantiation does not preserve the body of Christ in the sacrament and to claim that because Descartes believes God has the power to do anything, one has no certain knowledge of one's world. Régis shows that Malebranche's theory of seeing all things in God requires an impossible union of man with God. Jean Du Hamel is accused of failing to see that mental ideas that do not resemble their material objects still make these objects known. Régis insists that Benedict (Baruch) de Spinoza fails to see that God is not an ordinary substance and thus confuses the material world with God.
Like Rohault, Régis insists that reason and faith do not conflict. Reason is infallible in the order of nature; faith, in the order of grace. Events in one order cannot be explained with principles of the other. Thus, Régis offers no physical explanation of transubstantiation—as do Descartes, other Cartesians, and the scholastic physicists. He argues that transubstantiation is an event not in the order of nature but in the order of grace.
See also Arnauld, Antoine; Cartesianism; Descartes, René; Elisabeth, Princess of Bohemia; Essence and Existence; Huet, Pierre-Daniel; Malebranche, Nicolas; Regius, Henricus (Henry de Roy); Rohault, Jacques; Spinoza, Benedict (Baruch) de.
Watson, Richard A. The Breakdown of Cartesian Metaphysics. Indianapolis: Hackett, 1998. Originally published as The Downfall of Cartesianism, 1673–1712: A Study of Epistemological Issues in Late Seventeenth-Century Cartesianism (The Hague: Nijhoff, 1965).
Richard A. Watson (1967, 2005)