Baruch Spinoza

Baruch Spinoza, a prominent philosopher of the 17th century, was born on November 24, 1632, in Amsterdam and died on February 21, 1677, in The Hague. Early in his life, he agreed with René Descartes' philosophy of the mind-body dualism, but later changed his stance, asserting that they are not separate entities but one unified being.

Source: Wikipedia