Abstract

The essays in this volume are based on addresses given during a colloquium on free logic, modal logic, and related areas held at the University of California in 1968. The majority of the contributors are well known for their writings in these fields and their papers are as illuminating as they are technical. In the first paper, Lambert and Bas C. Van Fraassen apply free logic to several controversies in quantified modal logic. One of these is Putman's argument that 'Nothing is both red and green all over' can be had as a theorem of modal logic. Lambert and Van Fraassen provide a counter example to this claim and then show that the argument only holds in systems allowing possible individuals. Jaako Hintikka's essay also deals with 'free' modal logics in much the same way as Hintikka's other papers and discusses some of the criticisms of Quine of the entire enterprise of quantified modal logic. In another paper, H. Leblanc and R. K. Meyer provide truth-value semantics for the theory of types and hence an alternative semantic structure for functional calculi of any order. In addition to these essays, there are papers by R. Thomason and Dana Scott on modal logic, J. Vickers on probability logic, and Peter Woodruff on truth value gaps. To anyone interested in these various areas this collection is sure to be welcome.--R. P. M.