Richard Zach (University of Calgay, Canada)

Algebraic Semantics for Logics of Vagueness"

In his recent paper “True, Truer, Truest”, Brian Weatherson has argued for classical logic as the logic of vagueness by obtaining it from an algebraic (order theoretic) approach to vagueness based on a primitive relation of truer than, which yields a semantics in terms of Boolean lattices. The approach is similar–both in spirit and in the formal details–to approaches to vagueness based on other ordered structures, such as MV or Goedel algebras. The basic philosophical methodology of such an approach is, however, problematic in principle. Moreover, the details of the algebraic structures used are in conflict with some of the underlying pre-theoretic intuitions about “truer than.”

Libor Behounek (Institute of Computer Science of the Academy of Sciences of the Czech Republic)

“On the motivation of fuzzy logic”

The traditional [0,1] motivation falls short of explaining several features of fuzzy logic. An independent motivation based on general pre-theoretical assumptions will be given in the talk, and some features of fuzzy logic addressed (truth-functionality, non-idempotency of strong conjunction,

etc.).