Fuzzy Logic: An Interface Between Logic and Human Reasoning

I will not discuss here the alleged equivalence between fuzzy and two-valued logic; by choosing criteria established for the more restricted two-valued formalism, Elkan does not have a suitable framework for a meaningful comparison. To point out prerequisites for the practical usefulness of knowledge representation formalisms, I will focus on the role of fuzzy logic in linking two formally incommensurable worlds: the natural world of human perception and experience that leads to subjective cognitive concepts, and the formal world of classical logic that yields universal truth conditions.