THE COURTIER AND THE HERETIC

Matthew Stewart's DANGEROUS TO KNOW is an extraordinary portrait of the metaphysical crisis that occurred at the dawn of the modern world, as experienced by two of its greatest thinkers, Baruch de Spinoza and Gottfried Willhelm Leibniz.

Philosophy in the late seventeenth century was a dangerous business, and Spinoza (1632-1677) was a radical iconoclast at a time when that label could mean a death sentence. Conversely, Leibniz (1646-1716)-the last universal genius, inventor of the calculus, and a great metaphysician in his own right-defended Christian orthodoxy and the ancien regime. Leibniz spared no effort to distance himself publicly from the man he referred to as "the most dangerous and impious man of the century," and often stated that Spinoza's ideas, if widely disseminated, would destroy the moral foundations of society. However, in private Leibniz was consumed by Spinoza's work - going to extraordinary lengths to learn the contents of his unpublished manuscripts, cultivating relationships with his acquaintances, and even writing Spinoza directly under a flimsy pretext. The two men finally met in November 1676; Spinoza died not long after. Leibniz outlived Spinoza by forty years, and spent the rest of his life deeply but secretly engaged by his rival's work, ultimately coming to represent a radically different approach to the challenges of the modern era. Tracing the personal and philosophical development of each man, Stewart takes us deep into the foundations of modern history and philosophy during the radical enlightenment and counter-reformation - a crucial point in western history, richly peopled by the likes of Locke, Newton, Descartes, Huygens, and Rembrandt - making the arguments as vital today as they were to these great and influential minds. Part epic of personal rivalry, part philosophical thriller, Stewart's dramatic intellectual history is as entertaining at Wittgenstein's Poker, and as fluid as The Metaphysical Club. Matthew Stewart is the author of The Truth About Everything and Monturiol's Dream (Pantheon). He received his D.Phil. in philosophy from Oxford, and currently lives in New York.