Pierre Gassendi

Works

• 1644Disquisitio metaphysica

  Gassendi’s Fifth Objections to the Meditations, Descartes’ replies and Gassendi’s rejoinders, point by point: the mind knows itself and God only through ideas drawn from the senses, and existence could be inferred from any action, walking as well as thinking.

• 1658Syntagma philosophicum

  His posthumous system in logic, physics and ethics: Epicurus’ atoms and void, but created by God and finite in number, an immortal rational soul and a happiness of tranquil mind and painless body.

Position

Gassendi set out to replace Aristotle’s natural philosophy with that of Epicurus, purged of what a Christian could not accept. Matter consists of indivisible atoms moving in a void, but the atoms are created by God, finite in number and set in motion by him; the world is governed by providence, and besides the material soul that humans share with animals there is an immortal rational soul. In the theory of knowledge he took a middle way between dogmatism and Pyrrhonian scepticism: all knowledge starts from the senses, and reason reaches the appearances of things and their probable causes, not their inner essences. This was the basis of his objections to Descartes. The mind, he argued, has no idea of itself or of God that does not come from sensory experience; Descartes could have inferred his existence from any of his actions, not only from thinking; and it is unclear how a mind without extension could be united with a body. He addressed Descartes as “O mind”, and Descartes answered “O flesh”. His ethics follows Epicurus: happiness is tranquillity of mind and the absence of bodily pain. Through the abridgement of his philosophy by his pupil François Bernier (1674–1678) and through Walter Charleton in England his atomism reached Boyle, Locke and Newton, though how much each of them owed to him is still debated.

Life & context

Pierre Gassendi was born on 22 January 1592 in Champtercier near Digne in Provence, into a farming family. He studied at Digne and Aix, took a doctorate in theology at Avignon in 1614 and became a priest. From 1617 to 1623 he taught philosophy at the University of Aix, and his lectures against Aristotle became the first book of his Exercitationes paradoxicae adversus Aristoteleos (1624). When the Jesuits took over the college his teaching there ended; he remained a canon, and from 1634 provost, of the cathedral chapter of Digne. Through the antiquarian Nicolas-Claude Fabri de Peiresc and the Minim friar Marin Mersenne he joined the learned correspondence of Europe. In 1631 he was the first to observe a transit of Mercury across the Sun, which Kepler had predicted, and in 1640 he had a stone dropped from the mast of a moving galley at Marseille to show, in support of Galileo, that it lands at the foot of the mast. In 1641 he wrote the Fifth Objections to Descartes’ Meditations and in 1644 published the whole exchange with his rejoinders. Appointed professor of mathematics at the Collège royal in Paris in 1645, he gave up teaching after a few years because of illness. He wrote lives of Peiresc (1641) and of Epicurus (1647) and a large commentary on the tenth book of Diogenes Laertius (1649). He died in Paris on 24 October 1655; his Syntagma philosophicum appeared in his collected works (Lyon, 1658).

Further main works

• Exercitationes paradoxicae adversus Aristoteleos (book I, 1624)
• Fifth Objections to Descartes’ Meditations (1641)
• Life of Peiresc (Viri illustris Nicolai Claudii Fabricii de Peiresc vita, 1641)
• On the Life and Character of Epicurus (De vita et moribus Epicuri, 1647)
• Notes on the Tenth Book of Diogenes Laertius (Animadversiones in decimum librum Diogenis Laertii, 1649)