As modern thought derives its mechanical temper equally from both these sources, and the natural science of the day has appropriated the corpuscles of Descartes under the name of molecules, as well as the atoms of Gassendi, though not without considerable modification in both conceptions (Lange, vol. i. p. 269), so we find attempts at mediation at an early period. While Père Mersenne (1588-1648), who was well versed in physics, sought an indecisive middle course between these two philosophers, the English chemist, Robert Boyle, effected a successful synthesis of both. The son of Richard Boyle, Earl of Cork, he was born at Lismore in 1626, lived in literary retirement at Oxford from 1654, and later in Cambridge, and died, 1692, in London, president of the Royal Society. His principal work, _The Sceptical Chemist (Works_, vol. i. p. 290 _seq_.), appeared in 1661, the tract, _De Ipsa Natura_, in 1682.[1] By his introduction of the atomic conception he founded an epoch in chemistry, which, now for the first, was freed from bondage to the ideas of Aristotle and the alchemists. Atomism, however, was for Boyle merely an instrument of method and not a philosophical theory of the world. A sincerely religious man,[2] he regards with disfavor both the atheism of Epicurus and his complete rejection of teleology--the world-machine points to an intelligent Creator and a purpose in creation; motion, to a divine impulse. He defends, on the other hand, the right of free inquiry against the priesthood and the pedantry of the schools, holding that the supernatural must be sharply distinguished from the natural, and mere conjectures concerning insoluble problems from positions susceptible of experimental proof; while, in opposition to submission to authority, he remarks that the current coin of opinion must be estimated, not by the date when and the person by whom it was minted but by the value of the metal alone. Cartesian elements in Boyle are the start from doubt, the derivation of all motion from pressure and impact, and the extension of the mechanical explanation to the organic world. His inquiries relate exclusively to the world of matter so far as it was "completed on the last day but one of creation." He defends empty space against Descartes and Hobbes. He is the first to apply the mediaeval terms, primary and secondary qualities, to the antithesis between objective properties which really belong to things, and sensuous or subjective qualities present only in the feeling subject.[3] [Footnote 1: Boyle's _Works_ were published in Latin at Geneva, in 1660, in six volumes, and in 1714 in five; an edition by Birch appeared at London, 1744, in five volumes, second edition, 1772, in six. Cf. Buckle, _History of Civilization in England_, vol. i. chap. vii. pp. 265-268; Lange, _History of Materialism_, vol. i. pp. 298-306; vol. ii. p. 351 _seq_.; Georg Baku, _Der Streit über den Naturbegriff, Zeitschrift für Philosophie_, vol. xcviii., 1891, p. 162 _seq_.]