Spinoza shared to the fullest extent, and even went beyond, Descartes's ambition to reconstruct philosophy on a mathematical basis. The idea may have come to him from the French thinker, but it is actually of much older origin, being derived from Plato, the leading spirit of the Renaissance, as Aristotle had been the oracle of the later Middle Ages. Now Plato's ideal had been to construct a philosophy transcending the assumptions--or, as he calls them, the hypotheses--of geometry as much as those assumptions transcend the demonstrations of geometry; and this also was the ideal of Spinoza. Descartes had been content to accept from tradition his ultimate realities, Thought, Extension, and God, without showing that they must necessarily exist; for his proof of God's existence starts from an idea in the human mind, while Thought and Extension are not deduced at all. To appreciate the work of the Hebrew philosopher, of the lonely muser, bred in the religion of Jahveh--a name traditionally interpreted as the very expression of absolute self-existence--we must conceive him as starting with a question deeper even than the Cartesian {50} doubt, asking not How can I know what is? but Why should there _be_ anything whatever? And the answer, divested of scholastic terminology, is: Because it is inconceivable that there should be nothing, and if there is anything there must be everything. This universe of things, which must also be everlasting, Spinoza calls God. The philosophy or religion--for it is both--which identifies God with the totality of existence was of long standing in Greece, and had been elaborated in systematic detail by the Stoics. It has been known for the last two centuries under the name of Pantheism, a word of Greek etymology, but not a creation of the Greeks themselves, and, indeed, of more modern date than Spinoza. Historians always speak of him as a Pantheist, and there is no reason to think that he would have objected to the designation had it been current during his lifetime. But there are important points of distinction between him and those who preceded or followed him in the same speculative direction. The Stoics differed from him in being materialists. To them reality and corporeality were convertible terms. It seems likely that Hobbes and his contemporary, the atomist Gassendi, were of the same opinion, although they did not say it in so many words. But Descartes was a strong spiritualist; and Spinoza followed the master's lead so far, at any rate, as to give Thought at least equal reality with matter, which he also identified with Extension. It has been seen what difficulties were created by the radical Cartesian antithesis between Thought and Extension, or--to call them by their more familiar names--mind and body, when taken together with the intimate association shown by experience to obtain between them; and also how {51} Geulincx and Malebranche were led on by the very spirit