The cleverest defenders of a faith are its greatest enemies; for their subtleties engender doubt and stimulate the mind. And if this was so with the writings of Maimonides, so much the more was it the case with the commentaries of Ibn Ezra, where the problems of the old faith were more directly expressed, and sometimes abandoned as unanswerable. The more Spinoza read and pondered, the more his simple certainties melted away into wondering and doubt.

His curiosity was aroused to inquire what the thinkers of the Christian world had written on those great questions of God and human destiny. He took up the study of Latin with a Dutch scholar, Van den Ende, and moved into a wider sphere of experience and knowledge. His new teacher was something of a heretic himself, a critic of creeds and governments, an adventurous fellow who stepped out of his library to join a conspiracy against the king of France, and adorned a scaffold in 1674. He had a pretty daughter who became the successful rival of Latin for the affections of Spinoza; even a modern collegian might be persuaded to study Latin by such inducements. But the young lady was not so much of an intellectual as to be blind to the main chance; and when another suitor came, bearing costly presents, she lost interest in Spinoza. No doubt it was at that moment that our hero became a philosopher.

At any rate he had conquered Latin; and through Latin he entered into the heritage of ancient and medieval European thought. He seems to have studied Socrates and Plato and Aristotle; but he preferred to them the great atomists, Democritus, Epicurus and Lucretius; and the Stoics left their mark upon him ineffaceably. He read the Scholastic philosophers, and took from them not only their terminology, but their geometrical method of exposition by axiom, definition, proposition, proof, scholium and corollary. He studied Bruno (1548-1600), that magnificent rebel whose fires "not all the snows of the Caucasus could quench," who wandered from country to country and from creed to creed, and ever

more "came out by the same door wherein he went,”-searching and wondering; and who at last was sentenced by the Inquisition to be killed "as mercifully as possible, and without the shedding of blood"-i. e., to be burned alive. What a wealth of ideas there was in this romantic Italian!

First of all the master idea of unity: all reality is one in substance, one in cause, one in origin; and God and this reality are one. Again, to Bruno, mind and matter are one; every particle of reality is composed inseparably of the physical and the psychical. The object of philosophy, therefore, is to perceive unity in diversity, mind in matter, and matter in mind; to find the synthesis in which opposites and contradictions meet and merge; to rise to that highest knowledge of universal unity which is the intellectual equivalent of the love of God. Every one of these ideas became part of the intimate structure of Spinoza's thought.

Finally and above all, he was influenced by Descartes (1596–1650), father of the subjective and idealistic (as was Bacon of the objective and realistic) tradition in modern philosophy. To his French followers and English enemies the central notion in Descartes was the primacy of consciousness— his apparently obvious proposition that the mind knows itself more immediately and directly than it can ever know anything else; that it knows the "external world" only through that world's impress upon the mind in sensation and perception; that all philosophy must in consequence (though it should doubt everything else) begin with the individual mind and self, and make its first argument in three words: "I think, therefore I am" (Cogito, ergo sum). Perhaps there was something of Renaissance individualism in this starting-point; certainly there was in it a whole magician's-hat-full of consequences for later speculation. Now began the great game of epistemology,1 which in Leibniz, Locke, Berkeley, Hume

1 Epistemology means, etymologically, the logic (logos) of understanding (epi-steme),-i. e., the origin, nature and validity of knowledge.

and Kant waxed into a Three Hundred Years' War that at once stimulated and devastated modern philosophy.

But this side of Descartes' thought did not interest Spinoza; he would not lose himself in the labyrinths of epistemology. What attracted him was Descartes' conception of a homogeneous "substance" underlying all forms of matter, and another homogeneous substance underlying all forms of mind; this separation of reality into two ultimate substances was a challenge to the unifying passion of Spinoza, and acted like a fertilizing sperm upon the accumulations of his thought. What attracted him again was Descartes' desire to explain all of the world except God and the soul by mechanical and mathematical laws, an idea going back to Leonardo and Galileo, and perhaps reflecting the development of machinery and industry in the cities of Italy. Given an initial push by God, said Descartes (very much as Anaxagoras had said two thousand years before), and the rest of astronomic, geologic and all non-mental processes and developments can be explained from a homogeneous substance existing at first in a disintegrated form (the "nebular hypothesis" of Laplace and Kant); and every movement of every animal, and even of the human body, is a mechanical movement,-the circulation of the blood, for example, and reflex action. All the world, and every body, is a machine; but outside the world is God, and within the body is the spiritual soul.

Here Descartes stopped; but Spinoza eagerly passed on.

3. Excommunication

These were the mental antecedents of the externally quiet but internally disturbed youth who in 1656 (he had been born in 1632) was summoned before the elders of the synagogue on the charge of heresy. Was it true, they asked him, that he had said to his friends that God might have a body-the world of matter; that angels might be hallucina