Pierre Gassendi

Pierre Gassendi (French: [pjɛʁ gasɛ̃di]; also Pierre Gassend, Petrus Gassendi, Petrus Gassendus; 22 January 1592 – 24 October 1655) was a French philosopher, Catholic priest, astronomer, and mathematician. While he held a church position in south-east France, he also spent much time in Paris, where he was a leader of a group of free-thinking intellectuals. He was also an active observational scientist, publishing the first data on the transit of Mercury in 1631. The lunar crater Gassendi is named after him.

He wrote numerous philosophical works, and some of the positions he worked out are considered significant, finding a way between skepticism and dogmatism. Richard Popkin indicates that Gassendi was one of the first thinkers to formulate the modern "scientific outlook", of moderated skepticism and empiricism. He clashed with his contemporary Descartes on the possibility of certain knowledge. His best known intellectual project attempted to reconcile Epicurean atomism with Christianity.

Gassendi was born at Champtercier, near Digne, in France to Antoine Gassend and Françoise Fabry. His earliest education was entrusted to his maternal uncle, Thomas Fabry, the curé of the church of Champtercier. A youthful prodigy, at a very early age he showed academic potential and attended the collège (the town high school) at Digne, where he displayed a particular aptitude for languages and mathematics. In 1609 he entered the University of Aix-en-Provence, to study philosophy under Philibert Fesaye, O.Carm. at the Collège Royal de Bourbon (the Faculty of Arts of the University of Aix). In 1612 the college of Digne called him to lecture on theology. While at Digne, he travelled to Senez, where he received minor orders from Bishop Jacques Martin. In 1614 he received the degree of Doctor of Theology from the University of Avignon, and was elected Theologian in the Cathedral Chapter of Digne. On 1 August 1617 he received holy orders from Bishop Jacques Turricella of Marseille. In the same year, at the age of 24, he accepted the chair of philosophy at the University of Aix-en-Provence, and yielded the chair of theology to his old teacher, Fesaye. Gassendi seems gradually to have withdrawn from theology. He maintained his position as Canon Theologian at Digne, however, and in September 1619, when Bishop Raphaël de Bologne took possession of the diocese of Digne, Gassendi participated and made the speech on behalf of the Chapter.

He lectured principally on the Aristotelian philosophy, conforming as far as possible to the traditional methods while he also followed with interest the discoveries of Galileo and Kepler. He came into contact with the astronomer Joseph Gaultier de la Vallette (1564–1647), the Grand Vicar of the Archbishopric of Aix.

In 1623 the Society of Jesus took over the University of Aix. They filled all positions with Jesuits, so Gassendi was required to find another institution. He left, returning to Digne on 10 February 1623, and then returned to Aix to witness an eclipse of the moon on 14 April and the presence of Mars in Sagittarius on 7 June, from which he returned again to Digne. He travelled to Grenoble on behalf of the Chapter of Digne for a lawsuit, most reluctantly, since he was working on his project on Aristotle's paradoxes. In 1624 he printed the first part of his Exercitationes paradoxicae adversus Aristoteleos. A fragment of the second book later appeared in print at The Hague (1659), but Gassendi never composed the remaining five, apparently thinking that the Discussiones Peripateticae of Francesco Patrizzi left little scope for him.

He spent some time with his patron Nicolas Peiresc. After 1628 Gassendi travelled in Flanders and in Holland where he encountered Isaac Beeckman and François Luillier. He returned to France in 1631. In 1634 the Cathedral Chapter of Digne had become disgusted at the wasteful behavior of Provost Blaise Ausset, and they voted to replace him. They obtained an arrêt of the Parliament of Aix, dated 19 December 1634, which consented to his deposition and to the election of Gassendi as provost of the Cathedral Chapter. Gassendi was formally installed on 24 December 1634. He held the Provostship until his death in 1655.

During this time he wrote some works, at the insistence of Marin Mersenne. They included his examination of the mystical philosophy of Robert Fludd, an essay on parhelia, and some observations on the transit of Mercury.

Gassendi then spent some years travelling through Provence with the duke of Angoulême, governor of the region. During this period he wrote only the one literary work, his Life of Peiresc, whose death in 1637 seemed to afflict him deeply; it received frequent reprintings and an English translation. He returned to Paris in 1641, where he met Thomas Hobbes. He gave some informal philosophy classes, gaining pupils or disciples; according to the biographer Grimarest, these included Molière, Cyrano de Bergerac (whose participation in classes is disputed), Jean Hesnault and Claude-Emmanuel Chapelle, son of Lullier.