PETER SYLVAIN, a French philosopher, and a great propagator of the doctrines of Des Cartes, was born in Agenois in the year 1632. He studied languages and philosophy under the Jesuits at Cahors; and as his views were then directed to the church, he was afterwards occupied in the study of divinity at the university of that town. His progress in learning was so uncommon, that at the end of four years he was offered a doctor's degree without the usual charges; but he did not think it became him to accept of it till he had studied also in the Sorbonne at Paris. He went thither, but was soon disgusted with theology; and as the philosophy of Des Cartes began at that time to make a noise through the lectures of Rohault, he conceived a taste for it, and gave himself up entirely to it. He frequented these lectures; and becoming an adept, went to Toulouse in 1665, and read lectures in it himself. Having fine parts, a clear and fluent manner, and a happy way of making himself understood, he drew all sorts of people; the magistrates, the learned, the ecclesiastics, and the very women, who now all affected to abjure the ancient philosophy. In 1680 he returned to Paris; where the concourse about him was such, that the sticklers for Peripateticism began to be alarmed. They applied to the archbishop of Paris, who thought it expedient, in the name of the king, to put a stop to the lectures; which accordingly were discontinued for several months. The whole life of Regis was spent in propagating the new philosophy. In 1690 he published a formal system of it, containing logic, metaphysics, physics, and morals, in 3 vols. 4to, and written in French. It was reprinted the year after at Amsterdam, with the addition of a discourse upon ancient and modern philosophy. He wrote afterwards several pieces in defence of his system; in which he had disputes with M. Huet, Du Hamel, Malebranche, and others. His works, though abounding with ingenuity and learning, have been disregarded, in consequence of the great discoveries and advancement in philosophic knowledge that have been since made. He died in 1707. He had been chosen member of the academy of sciences in 1699.

The works of this author are the following:—A System of Philosophy, containing Logic, Metaphysics, and Morals; in 1690, 3 vols. 4to, being a compilation of the different ideas of Des Cartes.

The Use of Reason and of Faith.

An Answer to Huet's Censures of the Cartesian Philosophy; and an Answer to Du Hamel's Critical Reflections.

Some pieces against Malebranche, to show that the apparent magnitude of an object depends solely on the magnitude of its image, traced on the retina.

A small piece upon the question, Whether pleasure makes our present happiness?