Pierre Gassendi (; also Pierre Gassend or 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.
Biography
Early life 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.Fisquet, p. 249. 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.Bougerel (1737), p. 6. 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 Gassendi seems gradually to have withdrawn from theology.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.Fisquet, p. 250.
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.Bougerel (1737), pp. 8-9. Dictionary of Scientific Biography, Gassendi (Gassend), Pierre, retrieved: 2017-08-02.
Priesthood
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.J J O'Connor and E F Robertson, Pierre Gassendi, retrieved: 2017-08-02 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.Bougerel, p. 15. 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.Galileo Project page. Bougerel, p. 15. In 1624 he printed the first part of his . 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-Claude Fabri de Peiresc (Peirescius). After 1628 Gassendi travelled in Flanders and in Holland where he encountered Isaac Beeckman and François Luillier.The Archimedes Project, Gassendi, Pierre (actually Pierre Gassend) 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.Fisquet, pp. 248, 252, 256.
During this time he wrote some works, at the insistence of Marin Mersenne. They included his examination of the mystical philosophy of Robert Fludd,Epistolica Exercitatio, in qua precipua principia philosophiae Roberti Fluddi deteguntur, 1631. an essay on parhelia,Epistola de parheliis. and some observations on the transit of Mercury.
1640s
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.Patricia Springborg (editor), The Cambridge Companion to Hobbes's Leviathan (2007), p. 422. 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.
In 1640 Mersenne engaged him in controversy with René Descartes. His objections to the fundamental propositions of Descartes appeared in print in 1641; they appear as the Fifth Set of Objections in the works of Descartes and as a separate edition entitled with rejoinders. Though Descartes is often credited with the discovery of the mind-body problem, Gassendi, reacting to Descartes' mind-body dualism, was the first to state it.Cottinghm, Stoothof, Murdoch, Vol. II, CUP 1984, pp. 234-237 Gassendi's tendency towards the empirical school of speculation appears more pronounced here than in any of his other writings. Jean-Baptiste Morin attacked his De motu impresso a motore translato (1642). In 1643 Mersenne also tried to garner support from the German Socinian and advocate of religious tolerance Marcin Ruar. Ruar replied at length that he had already read Gassendi but was in favour of leaving science to science not to the church.Murr, Sylvia, ed. (1997) (in French), Gassendi et l'Europe, Paris: Vrin, .
In 1645 he accepted the chair of mathematics in the Collège Royal in Paris, and lectured for several years with great success. In addition to controversial writings on physical questions, there appeared during this period the first of the works for which historians of philosophy remember him. In 1647 he published the well-received treatise De vita, moribus, et doctrina Epicuri libri octo. Two years later appeared his commentary on the tenth book of Diogenes Laërtius.De vita, moribus, et placitis Epicuri, seu Animadversiones in X. librum Diog. Laër. Lyons, 1649; last edition, 1675. In the same year he had published the more important commentary Syntagma philosophiae Epicuri.Lyons, 1649; Amsterdam, 1684.
In 1648 ill-health compelled him to give up his lectures at the Collège Royal. Around this time he became reconciled to Descartes, after years of coldness, through the good offices of César d'Estrées.Desmond M. Clarke, Descartes: A Biography (2006), p. 377.
Death and memorial
Gassendi travelled in the south of France in the company of his protégé, aide and secretary François Bernier, another pupil from Paris. He spent nearly two years at Toulon, where the climate suited him. In 1653 he returned to Paris and resumed his literary work, living in the house of Montmor, publishing in that year lives of Copernicus and of Tycho Brahe. The disease from which he suffered, a lung complaint, had, however, established a firm hold on him. His strength gradually failed, and he died at Paris in 1655. A bronze statue of him (by Joseph Ramus) was erected by subscription at Digne in 1852. A large crater on the Moon is named after him.
Scientific achievements As part of his promotion of empirical methods and his anti-Aristotelian and anti-Cartesian views, Gassendi was responsible for a number of scientific 'firsts': He explained parhelia in 1629 as due to ice crystals. In 1631, Gassendi became the first person to observe the transit of a planet across the Sun, viewing the transit of Mercury that Kepler had predicted. In December of the same year, he watched for the transit of Venus, but this event occurred when it was night time in Paris. Use of camera obscura to gauge the apparent diameter of the Moon. Dropping a stone from the mast of a ship (in De motu) conserves horizontal momentum, removing an objection to the rotation of the Earth. Measurement of speed of sound (to about 25% accuracy), showing that it is invariant of pitch. Satisfactory interpretation of Pascal's Puy-de-Dôme experiment with a barometer in the late 1640s; this suggested a created vacuum is possible. He asserted and defended (in Syntagma philosophiae Epicuri, 1649) the notion that matter is made of atoms, following Epicurus.
In addition to these achievements, Gassendi performed work on determining longitude via eclipses of the Moon and on improving the Rudolphine Tables. He addressed the issue of free fall in De motu (1642) and De proportione qua gravia decidentia accelerantur (1646).
Writings
Edward Gibbon styled him "Le meilleur philosophe des littérateurs, et le meilleur littérateur des philosophes" (The greatest philosopher among literary men, and the greatest literary man among philosophers).
Henri Louis Habert de Montmor published Gassendi's collected works, most importantly the Syntagma philosophicum (Opera, i. and ii.), in 1658 (6 vols., Lyons). Nicolaus Averanius published another edition, also in 6 folio volumes, in 1727. The first two comprise entirely his Syntagma philosophicum; the third contains his critical writings on Epicurus, Aristotle, Descartes, Robert Fludd and Herbert of Cherbury, with some occasional pieces on certain problems of physics; the fourth, his Institutio astronomica, and his Commentarii de rebus celestibus; the fifth, his commentary on the tenth book of Diogenes Laërtius, the biographies of Epicurus, Nicolas-Claude Fabri de Peiresc, Tycho Brahe, Nicolaus Copernicus, Georg von Peuerbach, and Regiomontanus, with some tracts on the value of ancient money, on the Roman calendar, and on the theory of music, with an appended large and prolix piece entitled Notitia ecclesiae Diniensis; the sixth volume contains his correspondence. The Lives, especially those of Copernicus, Tycho and Peiresc, received much praise.
Exercitationes
The Exercitationes excited much attention, though they contain little or nothing beyond what others had already advanced against Aristotle. The first book expounds clearly, and with much vigour, the evil effects of the blind acceptance of the Aristotelian dicta on physical and philosophical study. The second book, which contains the review of Aristotle's dialectic or logic, throughout reflects Ramism in tone and method. One of the objections to Descartes became famous through Descartes's statement of it in the appendix of objections in the Meditations.
Animadversiones
His book Animadversiones, published in 1649, contains a translation of Diogenes Laërtius, Book X on Epicurus, and appeared with a commentary, in the form of the Syntagma philosophiae Epicuri. His labors on Epicurus have historical importance, but he has been criticized for holding doctrines arguably irreconcilable with his strong expressions of empiricism.