LEIBNITZ, lib'nits (Ger.. Leibniz), Gorr FRIED WILHELM VON (1646-1716). A German philosopher and mathematician, born in Leipzig. His father, who was professor of law at the uni versity. died when Leibnitz was six years old. He studied at the Nikolaischule of his native city, under Thomasius: entered the university with unusual preparation, in his fifteenth year, and selected the law as his profession, but de voted himself also to philosophy and literature. When seventeen years old he defended a remark able thesis. entitled De principio Indiridui, and during the following summer he spent some time at the University of Jena, studying mathe matics. In 1664 he published Specimen Dillicul tatis in •ure, and in 1666 des Combinatoria.
In that year he presented himself for the degree in In consequence of Ids youth, however, he was not permitted to take it at Leipzig, but a few months later. November, 1666, he received the degree of doctor juris from Alt doll. After pursuing further studies he had the good fortune to become a kind of protege of Baron von Boyneburg. ex-Prime Minister to the Elector of Mainz. At Boynehurg's sugges tion, he dedicated to the Elector an essay. Nora Jlethodus Discenthe Docendaolue Jurisprudentice (1667). This gained an appointment for Leib nitz in the Elector's service. Leibnitz now (166S 69) set to work to reform the Corpus Juris (q.v.). Meanwhile he published several theologi cal treatises. In 1670. at the age of twenty-four, he was appointed assessor on the bench of the upper court of appeals. which was the supreme court of the electorate. In 1672 he accompanied Boyneburg's sons to Paris, and there submitted to Louis X1V. a plan for the invasion of Egypt. Leibnitz's real intention in this memorandum was to divert Louis's attention from plans against Germany. From Paris be went to Lon don; both in Paris and in London he formed the acquaintance of the most eminent philoso phers, among them Newton. Huygens. and Malebranche. In 1676 Leibnitz entered the serv ice of the Duke of Brunswiek-Liineburg as libra rian and privy councilor. After a tour of his torical exploration. he prepared a series of works illustrating the history of the House of Bruns wick. He undertook likewise the scientific di rection and organization of the mines in the Harz. into which he introduced many improve ments: he took an active part in negotiations for Church and in the theological discus, sions connected therewith, which formed the sub ject of a protracted correspondence with Bossuet and with Misson. His private studies, however, were chiefly philosophical and philological. He was chief organizer and first president of the Society of Sciences of Berlin, which ,later be came the Berlin Academy; and he originated at both Dresden and Vienna projects for the establishment of similar bodies. It was to him, likewise, that Peter the Great owed the plan of the since celebrated Academy of Saint Peters burg. The Czar bestowed on Leibnitz a pension and the title of privy councilor. 1n 1;14 Leib nitz wrote the Jlonadologic iu French for Prince Eugene of Savoy. Toward the close of his life Leibnitz spent some time in further work on the annals of the House of Brunswick, and was drawn into a philosophical controversy with Samuel Clarke (q.v.). Before the close of the controversy he died rather unexpectedly at Han over, November 14, 1716. A monument has been erected to him in Hanover, and in 1883 a statue was unveiled in Leipzig.
Leibnitz was eminent in history, divinity, phi losophy, political studies, experimental science, mathematics, mining engineering, and even belles-lettres. But it is chiefly through his phil osophical reputation that he lives in history. He was greatly influenced by the ('artesian phi losophy; but he differed from Descartes both in his method and in some of his principles. In epistemology Leibnitz was an opponent of the doctrine that the mind, at birth. is a
tabula rasa. a blank tablet to be written on by experience. He maintained, on the contrary, that, although we are not born with ready-made knowledge in the sense of clear, distinct ideas, still there are "small. dark notions of the soul." which are not the mere passive receptions of im pressions. There may he perceptions of which we are not aware, or which are not aware of them selves. Indeed, in the last resort. Leibnitz denies reality of everything which is not a percipient or a perception. The perception may be very minute, so as not to he self-conscious, or it may be conscious of itself. In the latter ease it is called apperception. Growth in knowledge con sists in the process of clarification and distinction of ideas. Sense is not fundamentally different from intellect: it is only confused intellect. Nothing conies to the soul from without. Every thing it seems to acquire in the process of learn ing is originally possessed in obscure form. Vir tually-, therefore. all ideas are innate in the sense that they are not acquired: but the explicit con sciousness of them is acquired. That which has presentations is called by Leibnitz a monad. or a unity, just because it is thus a self-contained system of perceptions. not influenceable from without. It is described as having no windows through which it can look out upon the rest of the universe, but as mirroring the whole universe within itself. But because each monad mirrors the whole universe, each is in so far like the others; the perceptions in each are precisely alike in content; the only difference is that these perceptions may vary indefinitely in clearness and distinctness. Those monads in which all perceptions are obscure are called matter: from matter up to God there is no difference in kind, merely a difference in degree of clearness and distinctness of presentations. Monads are found in all stages of clearness of presentation. and each monad tends toward clarification and dis tinction of these presentations. Those tions which are merely clear, hut not distinct, i.e. which are not confused with others, but are not adequately known in themselves, are objects of empirical or contingent knowledge: those presentations which are both clear and distinct are objects of rational or necessary knowledge. The Validity of rational knowledge is guaranteed by the principle of contradiction; that of eMpirical knowledge by the principle of suffi cient reason. which Leibnitz was the first to introduce into a system of philosophy. In other words, necessary truths are analytical, contingent truths synthetical. The latter must have authentication from without; an adequate reason must be given for their validity. The former are authenticated by the fact that it is impossible to think their opposites. The changes that take place at the same time in various monads have no influence 011 each other. There is DO interaction. But there is a preestablished of such sort that presentations in one monad correspond to those in another. The rela tion between any two monads is likened to that between two clocks keeping perfect time. They do not influence each other's movements, but they keep together. This correspondence is due to the fact that God, the monad of monads, created all other monads in such a way that in their subsequent course of development their changes should harmonize. These monads are immortal. In choosing to create this world of monads, Cod selected the best of all possible worlds. Cod's wisdom gave Him an infinite range of choice; Ilis goodness determined the selection Ile made. This is Leibnitz's peculiar optimism, which does not assert that everything is perfectly good, but that the world as a whole is the best of all possible worlds. In this way Leibnitz sought to justify Cod in creating a world with evil in it. This is Leibnitz's theodicy.