LEIBNIZ, GOTTFRIED WILHELM VON

German philosopher, polyhistorian, and court adviser; b. Leipzig, July 1, 1646; d. Hanover, Nov. 14, 1716.

Life. Leibniz studied law, mathematics, and philosophy at Jena and Leipzig. There he became acquainted with, and was influenced by, the works of Aristotle and the scholastics, especially F. suÁrez, as well as contemporary mechanistic theories in the natural sciences. At 17 he wrote De principio individui (Leipzig 1663); at 20 he received the degree of doctor of laws in Altdorf, near Nuremberg. In 1667 Leibniz entered the service of the Archbishop-Elector of Mainz, J. P. Schönborn, who wielded considerable influence in the political life of the times. Leibniz spent the years from 1672 to 1676 as a diplomat in Paris, where he came into contact with prominent scientists, philosophers, and theologians, among them C. Huygens, E. Mariotte, N. malebranche, E. W. Tschirnhaus, and A. arnauld. Between his duties in Paris, he managed to go to London, where he corresponded with members of the Royal Society. On his return to Germany, he sought out and conferred with B. spinoza in Holland. While in Paris, Leibniz invented the infinitesimal calculus, which I. Newton had also discovered. Then, from 1776 on, Leibniz was court adviser and librarian for the Duke of Braunschweig-Lüneburg at Hanover, where he worked on the history of the Guelfs and made an excellent series of source studies. He carried on an extensive correspondence with leading figures in the Church, in science, and in politics, discussing even such practical economic matters as mining, water supply, and land cultivation. He set himself especially to the task of organizing science, founded the Society (later Academy) of Science at Berlin, and negotiated similar plans for Petersburg and Vienna. He interested himself also in the spread of Christianity and worked toward reuniting the two great Christian denominations. He was a Protestant by persuasion; however, toward the end of his life he became a solitary, opposed even to his own church.

Doctrines. The distinctive philosophical teachings of Leibniz may be discussed under the headings of logic and theory of knowledge; metaphysics and theodicy; and ethical, political, and religious theory.

Logic and Theory of Knowledge. Leibniz here adopted a rationalistic approach, combining in one synthesis the theory of recollection of Plato, the eternal law concept of the Stoics—which, for St. Paul, is written in the hearts of men (Rom 2.15)—the theory of the active intellect of the scholastics, the notion of the divine spark of the mystics, and the innate ideas of R. descartes. However, one cannot represent these innate ideas as "the public proclamations of a magistrate inscribed on a particular tablet." They are nothing more than the understanding or reason itself judging between true and false on the basis of immanent, aprioristic faculties and principles. The senses are also required, but only as a blind man requires a cane. They offer man only the occasion for the exercise of understanding, which alone can throw light on the concept and without which sensation remains empty.

Leibniz therefore distinguishes between two types of truth, factual truth (contingent truths or truths of fact and existence) and real truth (truths of essences). Only the latter are truths in the strict sense of the word; the former are obscured by the senses. Man must have recourse to the principle of sufficient reason (ratio sufficiens ) in making judgments; i.e., he can justify the connection between subject and predicate only if there is sufficient ground for doing so. Since not all interrelationships between things are accessible to sense experience, factual truths are only probabilities, properly speaking, and not real truths, which are always universally valid, necessary, and eternal. For a mind to be able to penetrate all relations it must resolve factual truths into real truths, as if everything that could accompany an essence were already contained in its concept. The divine mind may see in this way, but Leibniz would have had the human mind operate thus also. For this reason, he attempted to resolve facts into necessary truths and sense data into concepts by means of a typical rationalist oversimplification.

Moreover, this feature of his philosophy was one over which he was most enthusiastic. He referred to the process of reducing factual knowledge to necessary conceptual relations as the ars combinatoria or characteristica universalis. One could, he thought, establish characteristic symbols or figures for all existing things and develop an algebraic art of comprehension on the basis of a mathematical calculus. Thus with Raymond lull he became a forerunner of modern logistics (see logic, symbolic). He hoped in this way to be able to resolve all controversies and intellectual disputes. He also conceived his ars combinatoria as of help in spreading the faith. "For if missionaries can be led to use this language, they can establish the true religion that stands in complete harmony with reason and one need no longer fear defections from religion in the future."

Metaphysics and Theodicy. The central concept of Leibniz's metaphysics is the monad. He devised his theory while enlarging upon Descartes's notion of sub-stance. If the body, as Descartes had said, is extension only, then something of the essence, namely, its capacity for activity, is not accounted for. Substance must then be a unit of action, un être capable d'action. This unit of action might be regarded as an aggregate of forces, but this would have no reality if the substance itself were not real. On the other hand, substance cannot be extended, because it would admit of infinite divisibility and thus fail to be an ultimate force unit. Hence, substances must be extended, not as a mathematical point, but as an ultimate unit of a psychical nature, a monad. "Monads are then the real atoms of nature; in short, they are the elements of things."

The function of the monad is representation; every force, including the will, is a type of representation—but this too is a radical simplification. There is a differentiation in the intensity of representations; this extends from the most unconscious (in pure or "empty" monads) to conscious representation that approaches perception and thought (as in plants and animals), to that of self-conscious being (as in human souls), and finally to that of the divine monad, who mirrors all things with the utmost clarity because He is pure act (actus purus ). The ascent from absolutely motionless monads to pure act is, according to Leibniz, an unbroken continuum, for nature admits of no gaps (lex continui ), a principle that also underlies the infinitesimal calculus.

Every monad reflects the universe, and this without external stimuli. "Monads have no windows." For this reason, all monads have a similar content and harmonize with one another without having to interact causally: they are ruled by a preestablished harmony like that of two clocks that are set and wound together but run independently. Nevertheless, the differentiation of intensity in the representations serves as a principle of individuation. Without this, all substances would be identical—the principles of the identity of indiscernibles.

Since for Leibniz the monad took the place of the atom, he can be regarded as taking account of modern mathematical and mechanistic thought, which he knew, and also of classical metaphysics, whose teachings on form and entelechy he further advanced by combining them with the monad concept. He recognized that there are not only parts in nature—and mechanism took account of these alone—but also unities and associations and ends that were included in the concept of entelechy. Thus each monad comprehends other monads under it and organizes them into a unity. The human soul is such a monad substance. One finds such entelechies in the whole range of the organic, but surprisingly also in the inorganic. God is the monad of monads; He is the substance that makes all other substances possible.

By this teaching Leibniz attempted to avoid Spinoza's concept of undifferentiated substance, since his monad theory preserved individuality and particularly the human person with his freedom and self-determination. He went too far, however, for his reduction of the atom to something psychical or spiritual could not account for the nature of bodies. Although he regarded extension as a phenomenon bene fundatum, he actually was teaching a type of panpsychism. The implied dynamism is too one-sided, for it is necessary that force be opposed to something that is not force in order for it to be intelligible.

As for God's being the monad of all monads, this put Leibniz more in accord with tradition, where God is regarded as the Form of forms and pure act. He also adopted the standard proofs for the existence of God, even the ontological argument. There are difficulties in his teachings, however, for he conceived God as having created the best of all possible worlds (see optimism), and thus seemed to endanger God's freedom. Leibniz felt that he had not done so, asserting the best possible worlds included evil. In his theodicy he justified this by distinguishing between metaphysical, physical, and moral evil. The first is nothing more than the finitude of the world. Physical evil he equated with pain; God wills this indirectly as punishment for guilt, on the one hand, and for the greater good He wills to draw from it, on the other. He does not will moral evil as such, but permits it because man is free. Leibniz also sought to justify revelation in his theodicy. It never contradicts real truth, the truth of reason; it can, however, go beyond reason and especially beyond factual truth, which itself is without necessity. A similar stand was taken by a contemporary, J. A. comenius.

Ethical, Political, and Religious Theory. Leibniz opposed T. hobbes in advocating the reasonableness, the wisdom, and the goodness proper to God's order. Man is the being he is because of his spirit and freedom, and his habitat is the realm of spirit where God is both sovereign and father. This perfection must be served by both the law and the state. Law consists in wise and good order, with God as well as with man. If right were to be sought only in utility or in power, God would not differ from an all-powerful devil, Leibniz's philosophy of law stands in contrast with the utilitarianism of Hobbes, S. Pufendorf (1632–94), and C. Thomasius. He had a strong following, however, in R. Boscovich, J. F. Herbart, B. Bolzano, G. Teichmüller (1832–88), and R. H. lotze; he also influenced E. Becher (1882–1929) and A. N. white head.

See Also: rationalism.

Bibliography: Major works. Discours de métaphysique (1686) and La Monadologie (1714), Eng. Discourse on Metaphysics, Correspondence with Arnauld, and the Monadology, tr. g. r. montgomery (La Salle, Ill. 1962); Système nouveau de la nature … (1695); Nouveaux essais sur l'entendement humain (1704); Eng. tr. a. g. langley (2d ed. Chicago 1916); Essais de shéodicée (Amsterdam 1710); Principes de la nature et de la grâce (1714). Editions. Opera philosophica, ed. j. e. erdmann, 2 v. (Berlin 1839–40; repr. 1959); Die philosophischen Schriften, ed. c. i. gerhardt, 7 v. (Berlin 1875–90; repr. Hildesheim 1960–61); Sämtliche Schriften und Briefe, ed. Preussische Akademie der Wissenschaften (Berlin 1923–). Literature. f. c. copleston, History of Philosophy (Westminster Md. 1946–), v.4. j. hirschberger, History of Philosophy, tr. a. n. fuerst, 2 v. (Milwaukee 1958–59). y. belaval, Leibniz: Initiation à sa philosophie (Paris 1962). h. w.b. joseph, Lectures on the Philosophy of Leibniz (Oxford 1949). l. couturat, La Logique de Leibniz après des documents inédits (Paris 1901; rept. Hildesheim 1961). b. russell, A Critical Exposition of the Philosophy of Leibniz (new ed. London 1937). k. hilde-brandt, Leibniz und das Reich der Gnade (The Hague 1953). h.g. alexander, ed., The Leibniz-Clark Correspondence (Manchester, Eng. 1956). j. o. fleckenstein, G. W. Leibniz: Barock und Universalismus (Munich 1959). a. wildermuth, Wahrheit und Schöpfung: Ein Grundriss der Metaphysik des G. W. Leibniz (Winterthur 1960). j. jalabert, Le Dieu de Leibniz (Paris 1960). g. martin, Leibniz: Logik und Metaphysik (Cologne 1960). h. m. wolff, Leibniz: Allbeseelung und Skepsis (Bern 1961).

[j. hirschberger]