denied the Cartesian definition of matter, and did not entirely accept the laws of motion as formulated in the "Principles." From Spinoza, then, might he not get valuable aid in reaching a truer conception of things? Stimulated by this idea, he sought, and after some difficulty obtained, the favor of a personal acquaintance with Spinoza at the Hague, and was even allowed to take away with him a copy of the initial definitions, axioms, and propositions of the Ethica. His interest in the philosophy of Spinoza was, Dr. Stein contends, very great, as his correspondence with Schuller (1677-78) clearly shows. Thus, in a conversation with Eckhardt, in April, 1677, he maintains, with Spinoza, that the existence of God follows from his very nature (Deus est ens, de cujus essentia est existentia) . So, he holds that God esse ens a se, seu quod existentiam suam a se ipso, nempe a sua essentia, habeat (cf. Spinoza's definition of causa sui). He also accepts the view of Spinoza that pain is something positive, not a mere want or privation. On the publication of the Opera Posthuma in January, 1678, Leibniz read through the Ethica in a few days, and, in a letter which Dr. Stein prints in his Appendix, he says that it contains "a number of beautiful and true thoughts," together with certain "paradoxes" which he cannot accept. Of these "paradoxes" those which he most decidedly rejects are the denial of intellect and will to God as natura naturans, and the denial of final causes. We may say in fact that, when Leibniz began to see that Spinoza denied self-consciousness to God, and, therefore, reduced the processes of nature to a blind necessity, the hope he had entertained of finding in him the antidote to Descartes received its deathblow. Thus he was thrown into a state of mental unrest, which lasted till about 1686. Meantime he clung to his early faith that there was a divine purpose in the world, and his main problem was to reconcile this idea with the inviolability of law, which he held with equal tenacity. This explains why his polemic against Descartes is so bitter and unsparing. "I have no hesitation in saying," he writes in a letter to Philippi, 1679, "that the philosophy of Descartes leads to atheism." This harsh judgment he seeks to justify on the ground that Descartes virtually denies that there is any purpose in nature, inasmuch as he affirms that "matter assumes in succession all the forms of which it is capable," — in other words, is under the dominion of a blind necessity. Such a view, he says, necessarily leads to the denial of intelligence and will in God, and hence Spinoza is simply Descartes developed to his logical consequences.
In this period of search Leibniz seemed to find in Plato what he had in vain sought for in Spinoza. He repeatedly quotes the well-known passage of the Phædo, in which Socrates is made to say that only in the changeless idea of the 'good' can the ultimate explanation of the
