A contemporary of Isaac Newton, German philosopher and mathematician Baron Gottfried Wilhelm Leibniz (1646–1716) is considered by some to be a largely forgotten mathematician, although his contributions to the field were just as important as Newton’s. He is often called the founder of symbolic logic; he introduced the terms *coordinate, abscissas,* and *ordinate* for the field of coordinate geometry; he invented a machine that could do multiplication and division; he discovered the well-known series for pi (π) divided by 4 (π/4) that bears his name; and he independently developed infinitesimal calculus and was the first to describe it in print. Because his work on calculus was published three years before Isaac Newton’s, Leibniz’s system of notation was universally adopted.