Gottfried Wilhelm Leibniz
Gottfried Wilhelm Leibniz (1646–1716) was a German philosopher and mathematician.
He studied philosophy and mathematics at Leipzig University from the age of 15, and in a dissertation from 1663 he produced a first draft of the metaphysical theories which he developed in later writings. He continued to study law at the University of Jena and became a lawyer at the University of Altdorf in 1666. After a few years of residence in Paris and London, in 1676 he was appointed court librarian at the Duke of Hanover, a post he held until he died.
Leibniz is one of the forefront of mathematics. Independently and at about the same time, Leibniz and Newton discovered the infinitesimal calculus. They defined in different ways and with different terms derivation and integration of continuous functions. Leibniz's symbolism turned out to be best thought out and is the one still in use. At the same time as the Japanese Seki Kōwa, Leibniz founded the determinant theory, which plays a major role in the theory of linear equation systems.