Fuzzy logic; vagueness; truth values

We briefly discuss the indeterminacy phenomenon as a phenomenon having two facets: uncertainty and vagueness. Then we describe some basic principles of modern fuzzy logic and show that it constitutes a group of well established formal systems. We argue that till now, fuzzy logic provides most successful solutions when trying to grasp vagueness. Its model of vagueness is based on introducing degrees of truth with well established and substantiated structure that non-trivially generalizes classical logic. We also outline formal theories which model some of essential manifestations of vagueness headed by analysis of sorites.

We briefly discuss the indeterminacy phenomenon as a phenomenon having two facets: uncertainty and vagueness. Then we describe some basic principles of modern fuzzy logic and show that it constitutes a group of well established formal systems. We argue that till now, fuzzy logic provides most successful solutions when trying to grasp vagueness. Its model of vagueness is based on introducing degrees of truth with well established and substantiated structure that non-trivially generalizes classical logic. We also outline formal theories which model some of essential manifestations of vagueness headed by analysis of sorites.