The Dutch philosopher Baruch Spinoza ranks as a major thinker in the rationalist tradition, and his Ethics is a classic of Western philosophy. His writings express the crucial issues of metaphysics more clearly than in any thinker since Plato.

Baruch, or Benedict, Spinoza was born on November 24, 1632, in Amsterdam, where his Jewish family settled after fleeing Portugal. Little is known about his early education except that the young Spinoza showed a facility for languages and eventually mastered Spanish, Portuguese, Dutch, Hebrew, Latin, Greek, and German. In 1656 Spinoza was expelled by his congregation on charges of atheism.

For the next four years Spinoza worked as a teacher in a private academy in Amsterdam and his interests in mathematics, physics, and politics developed. From 1660 to 1663 he lived near Leiden wrote Principles of Cartesianism, Short Treatise on God, Man and His Well-Being, and the first book of Ethics.

Spinoza then moved...