Lotfi Zadeh

Lotfi A. Zadeh (1921–2017) was an Azerbaijani-American mathematician and computer scientist who founded fuzzy set theory and fuzzy logic in 1965, while a professor at the University of California, Berkeley. His 1965 paper "Fuzzy Sets" — initially rejected by multiple journals — introduced the radical idea that mathematical precision could accommodate, rather than eliminate, the graded categories of natural language. Zadeh later developed the theory of computing with words and soft computing, arguing that human reasoning operates not on numbers but on perceptions. His work has been described as either a profound expansion of formal methods or a dangerous relaxation of mathematical standards, a polarized reception that reflects deeper disagreements about the proper relationship between logic and the world.