This is one of the first books to apply fuzzy logic to social choice theory. The book first discusses the rationalization of choice functions and the factorization of fuzzy preference relations. It then covers various solution sets used with the problem of cycling. It also explores Arrow's famous impossibility theorem, Black's median voter theorem, and the Gibbard-Satterthwaite theorem. The book concludes with the implications of intuitionistic fuzzy set logic for Arrow's impossibility theorem.