The great philosopher of this period was John Locke (_b._ 1632; _d._ 1704). Locke had much to do with the governments of his time, and especially with that extraordinary agitator and speculator, Ashley, Lord Shaftesbury, whom he attended in his banishment, and did not return till the Revolution. Yet, though so much connected with government, office, and the political schemers, Locke remained wonderfully unworldly in his nature. His philosophical bias, no doubt, preserved him from the corrupt influences around him. He was a staunch advocate of toleration, and wrote three letters on Toleration, and left another unfinished at his death. In these he defended both religious and civil liberty against Jonas Proast and Sir Robert Filmer, advocates of the divine right of kings. His "Thoughts on Education" and his "Treatises on Government" served as the foundations of Rousseau's "Emile" and his "Contrat Social." Besides these he wrote numerous works of a theological kind, as "The Vindication of the Reasonableness of Christianity;" and in his last years, "A Discourse upon Miracles," "Paraphrases of St. Paul," and "An Essay for the Understanding of St. Paul's Epistles;" a work "On the Conduct of the Understanding," and "An Examination of Father Malebranche's Opinion of Seeing all Things in God." But his great work is his "Essay concerning the Human Understanding." This may be considered the first pure and systematic treatise on metaphysics in the English language; and though the pursuit of the science since his time has led to the rejection of many of his opinions, the work will always remain as an able and clearly-reasoned attempt to follow the method of Bacon in tracing the nature and operations of the understanding. In the department of philosophy flourished also Bishop Berkeley (_b._ 1684; _d._ 1753), author of "The Principles of Human Knowledge," whostartled the world with the theory that matter has no existence in the universe, but is merely a fixed idea of the mind; Dr. Mandeville, a Dutchman by birth, who settled in London, and published various medical and metaphysical works of a freethinking character; Hutchinson, an opponent of Dr. Woodward in natural history, and Newton in natural philosophy; and David Hartley, author of "Observations on Man." Bishop Butler, Warburton, Hoadley, Middleton, author of "A Free Inquiry into the Miraculous Powers of the Church," and Secker, Archbishop of Canterbury, were the leading theologians in the Church; but Dissent could also boast of its men of light and leading in Dr. Isaac Watts, author of a system of Logic and of the popular Hymns; Calamy, the opponent of Hoadley; Doddridge, and others.