The relationship between probability theory and fuzzy logic has long been an object of discussion and some controversy. The position articulated in this article is that probability theory by itself is not sufficient for dealing with uncertainty and imprecision in real-world settings. To enhance its effectiveness, probability theory needs an infusion of concepts and techniques drawn from fuzzy logic—especially the concept of a linguistic variable and the calculus of fuzzy if–then rules. In the final analysis, probability theory and fuzzy logic are complementary rather than competitive.