THE COURTIER AND THE HERETIC: LEIBNIZ, SPINOZA, AND THE FATE OF GOD IN THE MODERN WORLD By Matthew Stewart W.W. Norton & Company, 320 pages, $25.95

Author examines an epochal encounter between two philosophers

Reviewed by DONNA MARTIN

The two philosophers could hardly have been more different.

Baruch de Spinoza, born in Amsterdam in 1632, was a descendent of Jews who had fled the Spanish and Portuguese Inquisitions for the relative freedom of the Dutch Republic. A precocious student of the Jewish school at Amsterdam, fluent in Hebrew and thoroughly versed in the Bible, he was excommunicated from the Jewish community at age 24 for his heretical beliefs about the nature of God, the origins of the Bible and his rejection of personal immortality. Self-assured, even arrogant in his beliefs, he moved to The Hague, where, cloaked in anonymity, he published his Tractatus Theologico-Politicus. This work established him as one of the first great theorists of the modern secular state.

Gottfried Wilhelm Leibniz, born in Leipzig in 1646, was the son of a professor of moral philosophy at the University of Leipzig, a center of Lutheran studies since the time of the Reformation. A polymath from his earliest years, he taught himself Latin by the age of 12, studied Aristotle’s logic at 13 and matriculated at the University of Leipzig the following year. Although his father died when he was only 6, Gottfried was guided by a series of powerful men to a career in law and politics. One of his earliest and most influential mentors was Baron von Boineburg, a recent Catholic convert who was first minister to the powerful elector of Mainz. At Baron von Boineburg’s request, Leibniz drafted a set of essays, Catholic Demonstrations, which tried to supply a rational foundation for a united Christian church. At this point, before his 24th year, Leibniz embarked on his lifelong involvement in church politics with the idea that the state should be grounded not on the “divine right” of kings but on eternal truths.

The previously unheralded meeting between Leibniz and Spinoza, like the charged meeting of Niels Bohr and Werner Heisenberg in the play “Copenhagen,” is the central event of Matthew Stewart’s The Courtier and the Heretic. While few details are known of the meeting of the two philosophers in The Hague in November 1676, it is clear that Spinoza’s philosophy had a profound effect on Leibniz, 14 years Spinoza’s junior. The effect on Spinoza, who was to die only a few months later at age 44, went unrecorded.

At first blush it seems unlikely that the urbane insider, Leibniz, would seek out Spinoza, an apostate Jew. But Leibniz had a deep commitment to reason, which also formed the basis of Spinoza’s philosophy. In correspondence with other religious and political figures of the day, Leibniz was careful to cover his tracks, alluding to Spinoza and his work as if he knew him only by his despised reputation. Yet Leibniz, on a mission to Paris that he made last for four years, from 1672-76, read widely and was especially intrigued by Spinoza’s work. Ultimately he secured an appointment in the court of Hanover, where he would spend the remaining 40 years of his life, but in 1676, before he left Paris, he made contact with a friend of Spinoza, who would share with him the ideas of Spinoza’s Ethics, his as yet unpublished masterwork.

According to Leibniz’s notes on his conversation with Spinoza’s friend, Spinoza believed that “God alone is substance”; “all creatures are nothing but modes”; and “mind is the very idea of the body.” Leibniz, whose own philosophy was in its formative stages, then secured the fateful meeting in The Hague.

It is no accident that these two great philosophers of the 17th century, though from profoundly different backgrounds, were each seeking a new understanding of God.

Copernicus and Galileo had done away with the idea that the earth was the center of the cosmos. Even generations before Darwin, the advances of science had thrown into doubt the belief that the human being was the purpose of creation. Descartes’ conclusion that mind was what distinguished humans from other creatures and from mechanical principles was a sort of truce between established religion and the emerging sciences. For his critics, however, Descartes had created a “mind-body” dualism in which it was difficult to explain how, as distinct substances, mind and body could interact at all.

Spinoza rejected Cartesian dualism, saying that “man is a part of Nature and must follow its laws, and this alone is true worship.” In effect, according to Spinoza, God and Nature were one and the same.

After meeting Spinoza, Leibniz was convinced that Spinoza’s God was incompatible with orthodox belief. Clearly there was no place for the immortality of the soul or for a personal God who would work miracles or show compassion. Leibniz saw his charge as showing that God is a person, an intelligent being.

After an aborted attempt to publish his Ethics, Spinoza rightly feared public reaction. The book was published only after his death in 1677 as his Opera Posthuma. Leibniz obtained a copy of the book then, and in notes intended only for himself, vehemently disagreed with everything Spinoza said. In his own Discourse on Metaphysics, Leibniz asserted that in order for God to be good, God must be able to make choices. In fact, in a statement later to be derided by Voltaire, Leibniz asserted that God chose the best of all possible worlds. As a refutation to Spinoza’s claim that there was only one substance, God, Leibniz declared that the world was made up of an infinity of self-contained entities that he called monads, existing in a pre-established harmony. In effect, this was an “argument from design.”

Leibniz sought the approval of the renowned French Catholic theologian Antoine Arnauld, but his views were rejected. Despite his efforts to distinguish his views from those of Spinoza, Leibniz was doomed to be grouped with his intellectual nemesis as a rationalist. The 17th century saw the beginning of the modern secular state. It may be said that this state looks more like Spinoza’s free republic than Leibniz’s version of theocracy, but the beliefs that continue to guide individuals, such as faith in a personal God and the immortality of the soul, seem to follow more directly from Leibniz.

The biographical note on the author of The Courtier and the Heretic is teasingly brief: Matthew Stewart received his doctorate in philosophy from Oxford, founded a management consulting firm, then retired to a life of contemplation. Dr. Stewart obviously enjoys sharing the results of his contemplation with others; his writing is clear, often witty and engagingly gossipy, especially about Leibniz, whose vanity and penchant for flattery were made transparent by his vast collection of papers. Dr. Stewart’s subtitle, implying that the fate of God in the modern world rests on these two philosophers, seems overly ambitious, but he does make an impressive case that the unlikely meeting of Leibniz and Spinoza in the 17th century was an epochal event.

Writer Donna Martin served for many years as the editorial director of Andrews McMeel Publishing.

National Catholic Reporter, July 14, 2006