not vanish when their true interpretation is thoroughly grasped. Of all these difficulties that concerned with the nature of matter is of greatest importance to Berkeley. From misconceptions of the true nature of material sub stance have flowed, according to him, the materialism, scepticism, and infidelity which disfigured the age ; and all these are completely banished by the new principle. The applications of his principle and his own inclinations led Berkeley into other departments of science which he was not so well qualified to handla The first result of the principle, as he conceived it, is undoubtedly empiricism in the theory of cognition. The ultimate elements of know ledge are the minima of consciousness, preservative or representative ; pure thought and abstract ideas are not capable of being realized by the mind, and are therefore impossible. The only mathematical processes to which these minima can be subjected are addition and subtraction ; and consequently great part of the Common Place Book is occupied with a vigorous and in many points exceedingly ignorant polemic against the fundamental conceptions of the fluxional and infinitesimal calculus, a polemic which
Berkeley carried on to the end of his days.He soon began to appear as an author. In 1707 he published two short tracts on mathematics, and in 1709 the New Theory of Vision, in which he applied his new principle, though without stating it explicitly. The new theory is a critical examination of the true meaning of the externality which is apparently given in visual conscious ness, and which, to the unphilosophical mind, is the strongest evidence of the independent existence of outer objects. Such visual consciousness is shown to be ulti mately a system of arbitrary signs, symbolizing for us certain actual or possible tactual experience in fact, a language which we learn through custom. The difference between the contents of the visual and the tactual con sciousness is absolute ; they have no element in common. The visible and visual signs are definitely connected with tactual experiences, and the association between them, which has grown up in our minds through custom or habit, rests upon, or is guaranteed by, the constant conjunction of the two by the will of the Universal Mind. But this synthesis, whether on the objective side as the universal thought or course of nature, or on the subjective side as mental association, is not brought forward prominently by Berkeley. It was at the same time perfectly evident that a quite similar analysis might have been applied to tactual consciousness, which does not give externality in its deepest significance any more than visual ; but it was with deli berate purpose that Berkeley at first drew out only one side of his argument. In 1710 the new doctrine received its full statement in the Prindj)les of Hitman Knowledge, where externality in its ultimate sense as independence of all mind is considered ; where matter, as an abstract, un- perceived substance or cause, is shown to be an impossible and unreal conception ; where true substance is affirmed to be conscious spirit, true causality the free activity of such a spirit, while physical substantiality and causality in their new meaning are held to be merely arbitrary but constant relations among phenomena connected subjectively by suggestion or association, conjoined objectively in the Universal Mind In ultimate analysis, then, nature is conscious experience, and forms the sign or symbol of a divine, universal intelligence and will.
deacon, and in 1711 he delivered his Discourse on Passive Obedience, in which he deduces moral rules from the intention of God to promote the general happiness, thus working out a theological utilitarianism, which may with advantage be compared with the later expositions of Austin and Mill. From the year 1707 he had been engaged as college tutor; in 1712 he paid a short visit to England, and in April of the following year he was presented by Swift at court. His splendid abilities and fine courteous manners, combined with the purity and uprightness of his character, made him a universal favourite. While in London he published his Dialogues (1713), a more popular exposition of his new theory ; for exquisite facility of style these are perhaps the finest philosophical writings in the English language. In November of the same year he became chaplain to Lord Peterborough, whom he accom panied on the Continent, returning in August 1714. He travelled again in 1715 as tutor to the son of Dr Ashe, and was absent from England for five years. On his way home he wrote and sent to the French Academy the essay De Motu, in which is given a full account of his new con ception of causality, the fundamental and all-comprehensive thought in his philosophy. In 1721, during the disturbed state of social relations consequent on the bursting of the the great South Sea bubble, he published an Essay toivards preventing the Ruin of Great Britain, which shows the intense interest he took in all practical affairs. In the same year he returned to Ireland as chaplain to the duke of Graf- ton, and was made divinity lecturer and university preacher. In 1722 he was appointed to the deanery of Dromore, a post which seems to have entailed no duties, as we find him holding the offices of Hebrew lecturer and senior proctor at the university. The following year brought him an unexpected addition of fortune, Miss Vanhomrigh, Swift s Vanessa, having left him half her property. It would appear that he had only met her once at dinner. In 1724 he was nominated to the rich deanery of Derry, but had hardly been appointed before he was using every effort to resign it in order to devote himself to his enthusiastically conceived scheme of founding a college in the Bermudas, and extending its benefits to the Americans. With in finite exertion he succeeded in obtaining from Government a promise of 20,000, and, after four years spent in pre paration, sailed in September 1728, accompanied by some friends and by his wife, daughter of Judge Forster, whom he had married in the preceding month. Their destina tion was Rhode Island, where they resolved to wait for the promised grant from Government. Three years of quiet retirement and study were spent in the island. Berkeley bought a farm, made many friends, and endeared himself to the inhabitants. But it gradually became apparent that Government would never hand over the promised grant, if indeed they had ever seriously contemplated doing so. Berkeley was therefore compelled reluctantly to give up his cherished plan. Soon after his return he published the fruits of his quiet studies in Alciphron, or the Minute Philoso})her (1733), a finely written work in the form of dialogue, critically examining the various forms of free- thinking in the age, and bringing forward in antithesis to them his own theory, which shows all nature to be the language of God. The work was extremely popular. In 173-4 he was raised to the bishopric of Cloyne, and at once went into residence. The same year, in his Analyst, he attacked the higher mathematics as leading to frccthink- ing; this involved him in a hot controversy. The Querist, a practical work in the form of questions on what would now be called social or economical philosophy, appeared in three parts, 1735, 1736, 1737. In 1744 was pub lished the Siris, partly occasioned by the controversy with regard to tar-water, but rising far above the petty circum stance from which it took its rise, and in its chain of reflections revealing the matured thoughts and wide reading of its author, while opening up hidden depths in the Berkeleiau metaphysics. In 1751 his eldest son died, and in 1752 he removed with his family to Oxford for the sake
of his son George, who was studying there. On the even-