Benedict de (Baruch) Spinoza (1632-1677), like Descartes and Leibniz, was a philosopher immersed in mathematical and scientific investigation. The greatest single influence on his thought was Descartes; he corresponded with men of science, such as Oldenburg (secretary to the newly formed Royal Society) and Boyle, and became an acknowledged expert in the science of optics, making his living (according to some accounts) as a lensgrinder. He was educated at the Jewish College in Amsterdam, to which city his Jewish parents had come from Portugal to escape persecution. Excommunicated from the synagogue for his sceptical beliefs, he settled among a group of enlightened Christians, who had formed a philosophical circle of which he soon became the leader. Then, leaving Amsterdam, he lived a secluded unworldly existence, refused offers of money and academic distinctions, and even withheld his great Ethics from the press, as much from love of truth and intellectual independence as from any fear of the censor. He died of consumption, leaving his major work unpublished.