Rational calculus
It was Leibniz who sought to develop a perfect system of formal logic, based on an “alphabet of human thought” and governed by a carefully prescribed “rational calculus.” With such logical tools, Leibniz hoped that mankind could rid everyday life of its pervasive imprecision and irrationality. Of course, he never came close to succeeding in what can only be called a grandiose plan, but his attempts constituted the first real steps toward what we today call “symbolic logic.” In particular, his use of algebraic forumlas to denote logical statements was a significant advance beyond the verbal syllogisms of Greek logical theory.