Gassendi (GASSENDY, GASSEND), PIERRE, French philosopher and scientist; b. at Champtercier, a country place near Digne in Provence, January 22, 1592 (tombstone says IX cal. February, i.e. January 24); d. at Paris, October 24, 1655. He studied Latin and rhetoric at Digne, and philosophy at Aix, whence his father, Antoine, called him back to take charge of domestic affairs. However, he was appointed to succeed his former teacher of rhetoric at Digne at the age of 16, and his teacher of philosophy at Aix at the age of 19. His friends and patrons at Aix, Prior Gautier and Councillor Peiresc, recognized his character and talents from his first publication and helped him to enter the ecclesiastical state. He became doctor of theology at Aix and attained proficiency in Greek and Hebrew literature. To allow him leisure for his studies he was appointed a canon (c. 1623) and provost (c. 1625) at the cathedral of Digne. Until 1645 his studies interrupted only by a journey to the Netherlands in 1628—his only trip outside of France. In 1645, on the recommendation of Cardinal Richelieu, he was appointed by the king to a professorship of mathematics at the College Royal of France, which he reluctantly accepted, being granted the rare privilege of returning to his native soil whenever his health required it. On November 23, he delivered his inaugural address in presence of the cardinal. His lectures before a numerous and learned audience were astronomical rather than mathematical, and resulted, two years later, in the publication of his “Institutio Astronomica”. Meanwhile an inflammation of the lungs had obliged him to return to Provence. In 1653, he went back to Paris and was received in a friendly manner at the Chateau de Monmort, where a year later he fell seriously ill with intermittent fever. He was bled nine times, and, although he declared himself too weak for another bleeding, he submitted to the decision of the best doctors in Paris. He underwent the same operation five times more, after which his speech became mere whispering, and he expired quietly at the age of 63.
Gassendi, “the Bacon of France“, is specially noteworthy for his opposition to the Aristotelean philosophy, and for his revival of the Epicurean system. He wished the aprioristic methods then prevailing in the schools replaced by experimental proofs. His cosmology, psychology, and ethics are epicurean, except that he maintains the doctrine of the Creator and of Providence, and the spirituality and immortality of the soul. He thus attempts to build up a Christian philosophy upon Epicurus—an inconsistency, which is attacked by non-Christian, as well as Christian, philosophers. His views on the constitution of matter and his merits in regard to modern kinetic atomism are explained by Lasswitz. That Gassendi was neither “the father of materialism” nor a sceptic in the proper sense is shown by Kiefl (see Baldwin, op. cit. below). He corresponded with Hobbes, Mersenne, Christina of Sweden, and engaged in controversy with Fludd, Herbert, and Descartes.
That as an amateur astronomer, Gassendi was a persevering, attentive, and intelligent observer, is evident from his notebook carefully kept from 1618 until 1652 and filling over 400 pages. With a Galilean telescope he observed the transit of Mercury in 1631, predicted by Kepler, by projecting the sun’s image on a screen of paper. His instrument was not strong enough, however, to disclose the occultations and transits of Jupiter’s satellites, or the true shape of Saturn’s ring. The results of his astronomical work are analysed in Delambre’s “Histoire de l’Astronomie Moderne” (Paris, 1821, II). Other works of minor importance refer to biographies, physics, and anatomy. Gassendi was in correspondence with Cassini, Galilei, Hevel, Kepler, Kircher, Scheiner, Vallis, and other scientists. As to the Copernican system, he maintained that it rested on probabilities, but was not demonstrated, although he ably refuted all objections against it. To those whose conscience forbade them to accept Copernicanism, he said that the Tychonian system recommended itself as the mist probable of all.
In character, Gassendi was retiring and unpretentious. With friends, he would give way to a humorous and ironical vein; in controversy, he observed the Socratic method. On Sundays and feast days he never omitted celebrating Mass; and when in Paris, he went to the church for his friend, Pere Mersenne. In his last illness he asked for the Viaticum three times, and for extreme unction, and his aspirations were words from the Psalms. Gassendi was esteemed by all, and loved by the poor, for whom he provided in lifetime and in his last will. He founded two anniversary Masses for himself, one to be said in the cathedral of Digne, and one in the chapel of his friend, Monmort, at St-Nicolas-des-Champs, Paris, where he was buried. The accompanying picture represents his marble bust in that mausoleum. The assertion that he was a Minorite is without foundation.
Gassendi’s “Opera Omnia” were edited in 6 vols., Lyons, 1658, and Florence, 1727.
J. G. HAGEN