"Neither riches, nor sensuous enjoyment, nor honours, can be a true good for man"; but on the contrary, "that the only thing which is able to fill the mind with ever-new satisfaction is the striving after knowledge, by means of which the mind is united with that which remains constant while all else changes."
"The God-intoxicated," was the name given to Spinoza long afterwards in Germany. He died (like St. Francis) at forty-five, worn out with the toil of thought. And it renews one's faith in the perspicacity of commonplace people to learn that his barber, sending in a bill after the death of the philosopher, alluded to his late customer as "Mr. Spinoza of blessed memory." It was left to a contemporary theologian to describe him as "an unclean and foul atheist."
Leibniz.—Spinoza had taken over from Descartes and Hobbes their mechanical and determinist conception of nature, though he gave to it, as we have seen, an interpretation of his own. His attitude was a blend of that rationalism and mysticism which were characteristic of so much seventeenth century thought. A far more complete reaction, however, displays itself in the system of a contemporary of Spinoza's—Gottfried Wilhelm Leibniz (1646-1716); who, when already a youth, had become an enthusiastic devotee of the new science; the study of Kepler, Galileo and Descartes caused him to feel as though "transported into a different world." Though a German by birth, Leibniz lived continuously in France, and wrote habitually in the language of that country.
Contrast to Spinoza.—Spinoza and Leibniz stand as examples of two distinct methods of eluding the despotism of mechanics—methods which will meet us again in the course of our survey. Spinoza accepts the mechanical view as being inevitable and even desirable, but subjects it to a spiritual interpretation—he regards it as the way in which the Natura naturans works.[9] Leibniz, on the other hand, viewed existence from an entirely different standpoint. He was bold enough to reject the mechanical view altogether; or rather he preferred to regard it as a convenient abstraction, or a useful formula, which might reflect certain aspects of reality, but could not do justice to its concrete richness and complexity.
A Philosophy of Individuals.—Leibniz's criticism of Descartes and the mechanical school proceeded along different lines from that of Spinoza, who, as we have seen, accepted the mechanical view as the basis of his speculation.
An axiom of that view was (as we know) the conservation of motion. For this conservation of motion, Leibniz substitutes the conservation of force as being logically the more fundamental concept. True reality, according to him, is not motion itself, but the force which is its cause. Force and existence became for him identical terms; to work and to exist were the same. That force is the true reality, Leibniz expressed in the language of his time by saying, "Force is substance, and all substance is force"—a proposition which would not be repudiated by modern science—and upon this statement his philosophy is built.
But it was not "force in general" or some "universal force" that was regarded by him as the final reality: Leibniz was not a forerunner of Herbert Spencer. Reality for him consisted in individual centres of force—a multitude of individual and independent beings, each with its own idiosyncrasy, and following its own lines. Existence was, in fact, for him, individual. It was the individual centres of force—not general principles, universal substances, laws or forces—that make up reality.
Doctrine of Monads.—This view of reality was formulated by Leibniz in his famous doctrine of "monads." "Monad" was the technical name applied by him to those absolute individuals which he regarded as constituting true reality. The word, meaning "unity," was simple and appropriate. And he declared that the "monad," to be rightly understood, must be regarded as analogous to our own souls. This principle of analogy was described by Leibniz as mon grand principe des choses naturelles. Thus reality was interpreted by him not in physical but in psychical terms, or if the expression be preferred, in terms of personality.[10]
Of these "monads" there exist, according to this view, infinitely many degrees. In fact all existence differs only in degree from our own. Even between mind and matter there is only a quantitative and not a qualitative gulf. For there are sleeping, dreaming, and more or less waking monads; and matter is a form of unconscious mind; the monads which compose material objects being "minds without memory," "momentary minds."
Let Leibniz speak for himself:—