After the Cartesian philosophy had given decisive expression to the tendencies of modern thought, and had been developed through occasionalism to its completion in the system of Spinoza, the line of further progress consisted in two factors: Descartes’s principles—one-sidedly rationalistic and abstractly scientific, as they were—were, on the one hand, to be supplemented by the addition of the empirical element which Descartes had neglected, and, on the other, to be made available for general culture by approximation to the interests of practical life. England, with its freer and happier political conditions, was the best place for the accomplishment of both ends, and Locke, a typically healthy and sober English thinker, with a distaste for extreme views, the best adapted mind. Descartes, the rationalist, had despised experience, and Bacon, the empiricist, had despised mathematics; but Locke aims to show that while the reason is the instrument of science, demonstration its form, and the realm of knowledge wider than experience, yet this instrument and this form are dependent for their content on a supply of material from the senses. The emphasis, it is true, falls chiefly on the latter half of this programme, and posterity, especially, has almost exclusively attended to the empirical side of Locke’s theory of knowledge in giving judgment concerning it.
John Locke was born at Wrington, not far from Bristol, in 1632. At Oxford he busied himself with philosophy, natural science, and medicine, being repelled by the Scholastic thinkers, but strongly attracted by the writings of Descartes. In 1665 he became secretary to the English ambassador to the Court of Brandenburg. Returning thence to Oxford he made the acquaintance of Lord Anthony Ashley (from 1672 Earl of Shaftesbury; died in Holland 1683), who received him into his own household as a friend, physician, and tutor to his son (the father of Shaftesbury, the moral philosopher), and with whose varying fortunes Locke’s own were henceforth to be intimately connected. Twice he became secretary to his patron (once in 1667—with an official secretaryship in 1672, when Shaftesbury became Lord Chancellor—and again in 1679, when he became President of the Council), but both times he lost his post on his friend’s fall. The years 1675-79 were spent in Montpellier and Paris. In 1683 he went into voluntary exile in Holland (where Shaftesbury had died in January of the same year), and remained there until 1689, when the ascension of the throne by William of Orange made it possible for him to return to England. Here he was made Commissioner of Appeals, and, subsequently, one of the Commissioners of Trade and Plantations (till 1700). He died in 1704 at Gates, in Essex, at the house of Sir Francis Masham, whose wife was the daughter of Cudworth, the philosopher.