Leibnitz (more accurately but less commonly LEIBNIZ), GOTTFRIED WILHELM, distinguished for almost universal scholarship, especially in philosophy and mathematics, was born on 1st July 1646 at Leipzig, where his father (died 1652) was professor of Moral Philosophy. He attended the Nicolai school in Leipzig, but learned much more from independent study—he taught himself to read Livy whilst still a boy of eight—and at fifteen entered the university of Leipzig to study law. He spent some time also at Jena working at mathematics. Being refused his doctor's degree at Leipzig on account of his youth in 1666, he graduated at Altdorf, the university town of Nuremberg. In the following year he gained a warm and admiring patron in Baron von Boineburg, formerly chief minister to the archbishop-elect of Mainz. At Boineburg's suggestion he presented to the elector his Nova Methodus Docendi Discendique Juris, containing a proposed reform of the Corpus Juris and of the teaching of jurisprudence; and the elector took the young scholar into his service. Amongst other duties in which Leibnitz employed his pen was to advocate, in 1669, the claims of the count palatine of Neuburg to the crown of Poland. Three years later he was summoned to Paris to explain at greater length the views he had laid down in an essay entitled Consilium Ægyptiacum, which elaborated a plan for the conquest of Egypt; though the real object of the work was to divert the attention of Louis from projects in and upon the German states. This plan of Leibnitz is believed to have suggested the invasion of Egypt which Napoleon attempted in 1798. The tour was extended to London, where Leibnitz became acquainted with Oldenburg, Boyle, and Newton; in Paris he had already learned to know Arnauld, Malebranche, and Huygens. His intercourse with Huygens and Newton stimulated his interest in mechanical and mathematical questions: he invented a calculating machine and devised what was in many respects a novel method of the Calculus (q.v.; and see NEWTON, FLUXIONS). This gave rise to a controversy with Newton as to which of them first invented this valuable mathematical method. In 1676 Leibnitz quitted the service of Mainz, and entered that of Hanover. The duke appointed him custodian of the library at Hanover; and this city was henceforth Leibnitz's headquarters. But his energies found scope outside the library: he effected improvements in the drainage of the mines in the Harz and in the coinage, arranged the library at Wolfenbüttel (where Lessing afterwards laboured), and in 1687 visited various cities in Germany, Austria, and Italy to gather materials for an exhaustive history of the Brunswick ducal house. The pope offered him the headship of the Vatican Library; but Leibnitz declined the offer, since the acceptance of it would have compelled him to become a Roman Catholic. The task of working up his materials into connected history employed a good deal of his time in subsequent years. Philosophy, too, absorbed a large proportion of his most serious thought. And in the discussions that were carried on with a view to the reconciliation of the Protestant and Roman Catholic churches Leibnitz took a prominent part, his principal correspondent being Bossuet. In 1686 there was published from his pen the Systema Theologicum, composed as a response—conciliatory—from the Protestant side to Bossuet's Exposition de la Foi. Subsequently, on the failure of these negotiations, Leibnitz endeavoured, but with the same want of success, to reconcile the Lutheran and the Reformed churches of Prussia. He was more successful in enlisting the interests of reigning princes in scientific societies. He induced Frederick I. of Prussia to found (in 1700) the Society of Sciences at Berlin, and was himself made first president; and he suggested the establishment of similar societies in St Petersburg, Dresden, and Vienna, which were afterwards instituted in each of those capitals. Whilst on a visit to Vienna in 1712–14 he was created a privy-councillor of the empire; he was also made a baron (Freiherr) of the empire. When George of Hanover ascended the throne of England Leibnitz, who some years before had vigorously supported his father's claims to the elector's hat, was disappointed at not being invited to accompany him. But shortly afterwards he died, on 14th November 1716, at Hanover.
The philosophy of Leibnitz holds an intermediate place between the dualism of Descartes and the monism of Spinoza (whom he visited at Amsterdam in 1676). His system is individualistic and dogmatic. He taught that the primary and essential quality of all substance is active force. Substance exists only in the form of atoms or monads, which are simple and similar in constitution, but differ qualitatively: each is a self- contained individuality. All monads possess two intrinsic properties—perception, or the capacity to mirror the universe, and appetite or striving. The degree of perfection with which each monad reflects the universe depends upon its individual character—i.e. upon the peculiar consensus or balance of relations that exist between the active and the passive elements in its nature. And the entire series of monads, from the very highest (God) to the very lowest, were so constituted, and so arranged from the first, that, whilst each obeys the laws of its own self-determined development independently of all others, it is at every moment in complete accord and harmony with all the rest. The body of man is a complex of separate monads; his soul is a single monad, the substantial centre of his being. Yet no monad can act upon another monad; the active force of each cannot pass out of itself. But the doctrine of general 'pre-established harmony' explains how and what relations do subsist between them, and so between body and soul. He compares body and soul to two clocks which have been constructed in the beginning in such a way, and so perfectly, that both can be depended upon to keep exact time with each other without any bond of connection or any interference from without. God is the primary, supreme, perfect monad; from Him all others proceed as 'fulgurations' or radiations. Plants and stones are likewise monads; but in their case the perceptive capacity is more or less blurred or slumbering—an adumbration of the modern doctrine of unconscious perception. Since God is the contriver of the universal harmony that prevails amongst all created things, this world must be the best of all possible worlds (see OPTIMISM). The real cogency of Leibnitz's argument depends upon his great logical instrument, the principle of sufficient reason: there is a sufficient reason why this world should be the best of all possible worlds, and there is no sufficient reason why it should be otherwise. His theory allowed him to demonstrate that there is a substantial agreement between faith and the deliverances of reason. The Leibnitzian ethics are deduced from the property of striving inherent in every monad—the final aim being perfection, reached through individual freedom.
Leibnitz was also a pioneer in the science of comparative philology. He took steps to collect specimens of various distant languages, in Asia and elsewhere, and studied them in a scientific manner. He recognised two great divisions of speech, the Aramaic, which included Arabic and Hebrew, and the Japhetic or Celto-Scythian, which coincided pretty nearly with what was subsequently called the Indo-Germanic or Aryan family of speech. Cf. Max Müller, Science of Language.
Leibnitz left no complete systematic account of his philosophical views. They have to be gathered from several collections of letters, essays contributed to the journals Acta Eruditorum, Journal des Savants, &c., and a few treatises, such as De Principio Individui (1663); Essai de Théodicée sur la Bonté de Dieu, la Liberté de l'Homme, et l'Origine du Mal (1710); Principes de la Nature et de la Grâce (1718); Monadologie (1714); and Nouveaux Essais sur l'Entendement (1765). In this last work he closely criticises Locke's celebrated Essay on the Human Understanding; and supplements the English philosopher's maxim of Nihil est in intellectu quod non fuerit in sensu, by adding nisi ipse intellectus. Editions of Leibnitz's writings have been published, though none is complete, by Dutens (6 vols. Geneva, 1768), by Pertz and Gerhardt (19 vols. 1843–90), and by O. Klopp (11 vols. 1862–84). The best Life is Guhrauer's (2 vols. 1842–46). See also biographical works by Kirchner (1877) and E. Pfeiderer (1870), and Bodemann on his Correspondence (1889). Feuerbach (1837), Zimmermann (1847, &c.), and K. Fischer (1867) have written on his philosophy.