Tarski on truth and logical consequence

Abstract

Tarski's writings on the concepts of truth and logical consequence rank among the most influential works in both logic and philosophy of the twentieth century. Because of this, it would be impossible to give a careful and accurate account of how far that influence reaches and of the complex route by which it spread. In logic, Tarski's methods of defining satisfaction and truth, as well as his work pioneering general model-theoretic techniques, have been entirely absorbed into the way the subject is presently done; they have become part of the fabric of contemporary logic, material presented in the initial pages of every modern textbook on the subject. In philosophy, the influence has been equally pervasive, extending not only to work in semantics and the philosophies of logic and language, but to less obviously allied areas such as epistemology and the philosophy of science as well. Rather than try to chart the wide-ranging influence of these writings or catalog the important research they have inspired, I will concentrate on various confusions and misunderstandings that continue to surround this work. For in spite of the extensive attention the work has received in the past fifty years, especially in the philosophical literature, misunderstandings of both conceptual and historical sorts are still remarkably widespread. Indeed in the philosophical community, recent reactions to Tarski's work on truth range from Karl Popper's “intense joy and relief” at Tarski's “legitimation” of the notion [1974, p. 399], to Hilary Putnam's assessment that “as a philosophical account of truth, Tarski's theory fails as badly as it is possible for an account to fail” [1985, p. 64]. Opinions have not exactly converged.