Benedict de Spinoza (November 24, 1632 - February 21, 1677) was one of Western Civilization's greatest philosophers.Revealing considerable scientific aptitude, the breadth and importance of Spinoza's work was not fully realized until years after his death. By laying the groundwork for the 18th century Enlightenment he came to be considered one of the great rationalists of the 17th-century philosophy. And his magnum opus, the posthumous Ethics, in which he opposed Descartes' mind-body dualism, has also earned him recognition as one of Western philosophy's most important contributors.