Thinker · TH-0273
Lotfi Zadeh
Lotfi Zadeh was an engineer and mathematician, born in Baku and raised in Tehran, who spent most of his career at the University of…
Also known as Lotfi A. Zadeh, Lotfi Asker Zadeh
1921 – 2017 · Baku, Tehran, New York, Berkeley (California)
Traditions: Analytic
Lotfi Zadeh was an engineer and mathematician, born in Baku and raised in Tehran, who spent most of his career at the University of California, Berkeley. His 1965 paper 'Fuzzy Sets' introduced sets whose membership comes in degrees between 0 and 1, the basis of fuzzy logic. The idea became a widely used tool in control engineering and computing, and a reference point in philosophical work on vagueness and many-valued logic.
Key ideas
- A fuzzy set assigns each object a degree of membership anywhere between 0 and 1, rather than a simple in-or-out.
- Fuzzy logic generalises classical connectives to graded truth values, giving a way to reason with vague predicates such as 'tall' or 'warm'.
- Approximate reasoning with linguistic variables can model how people make decisions with imprecise information.
- Possibility theory, built on fuzzy sets, offers an alternative to probability for representing some kinds of uncertainty.
Major works
- Fuzzy Sets (1965)
- Outline of a New Approach to the Analysis of Complex Systems and Decision Processes (1973)
- Fuzzy Sets as a Basis for a Theory of Possibility (1978)