Superstitious persons, who know better how to rail at vice than how to teach virtue, and who strive not to guide men by reason, but so to restrain th… - Benedictus de Spinoza

Hegel's History of Philosophy presents French materialism as the realization of Spinozistic Substance, which in any case is more comprehensible than the "French school of Spinoza."

The latter [Descartes] had sharply divided nature into mind and matter, i.e., thinking and extended substance, and had also placed God and the world in complete opposition to each other; Spinoza also, so long as he was a Cartesian, taught all that in his “Cogitatis Metaphysicis,” c. 12, i. I., 1665. Only in his later years did he see the fundamental falseness of that double dualism; and accordingly his own philosophy principally consists of the indirect abolition of these two antitheses. Yet partly to avoid injuring his teacher, partly in order to be less offensive, he gave it a positive appearance by means of a strictly dogmatic form, although its content is chiefly negative. His identification of the world with God has also this negative significance alone. For to call the world God is not to explain it: it remains a riddle under the one name as under the other. But these two negative truths had value for their age, as for every age in which there still are conscious or unconscious Cartesians.

Some important intellectual figures of the day made their way to the modest rooms he rented in the Hague in his last years, including the up-and-coming young go-getter Gottfried Wilhelm Leibniz, who would emerge as one of the most dazzling figures in the seventeenth century's impressive lineup of genius. Leibniz spent a few days with Spinoza, conversing on metaphysics. The only written record of their extensive conversations was a slip of paper on which Leibniz had written down, for Spinoza's approval, a proof for God's existence. Leibniz was profoundly influenced by Spinoza's ideas but sought always to conceal his philosophical debt, and is on record as denouncing the philosopher. When a professor of rhetoric at the University of Utrecht, one Johan Georg Graevius, wrote to Leibniz, castigating the Tractatus Theologico-Politicus as a "most pestilential book," whose author "is said to be a Jew named Spinoza, but who was cast out of the synagogue because of his monstrous opinions," Leibniz prudently chimed in with his own diplomatic calumny: "I have read the book by Spinoza. I am saddened by the fact that such a learned man has, as it seems, sunk so low."