Tarski's conception of logic

In its widest scope, Tarski thought the aims of logic should be the creation of “a unified conceptual apparatus which would supply a common basis for the whole of human knowledge.” Those were his very words in the Preface to the first English edition of the Introduction to Logic (1940). Toward that grand end, in the post-war years when the institutional and financial resources became available, with extraordinary persistence and determination Tarski campaigned vigorously on behalf of logic on several fronts from his increasingly powerful base at the University of California in Berkeley. The first order of business was to build up a school in logic bridging the university’s Mathematics and Philosophy Departments, and the opening wedge in that was the hiring of Leon Henkin as Professor of Mathematics in 1953. From then on, Henkin was Tarski’s right-hand man in the logic campaigns, locally, nationally and internationally, but he had other allies, both in Mathematics and in Philosophy. The first goal was to increase the proportion of logicians on the mathematics faculty to 10% of the whole; that took a number of years, eventually achieved with the appointment of Addison, Vaught, Solovay, Scott, Silver, Harrington and McKenzie. Through his influence in Philosophy, he succeeded in recruiting Myhill, Craig, Chihara and Sluga. Hans Sluga tells a story which gives a vivid picture of how Tarski operated: they met in 1966 when Tarski was in London to give the Shearman Lectures at Bedford College. Sluga, then a young faculty member interested in the philosophy of logic, was delegated to show him around. Personally impressed, at the end of his stay Tarski asked Sluga if he would like to come to Berkeley. Sluga said, “You mean permanently?” Tarski replied, “Yes.” Sluga said, “You mean you can invite me just like that?” and Tarski said, “If I tell them to take you, they will take you.” A formal bridge between mathematics and philosophy in Berkeley was forged with the establishment in 1959 of the interdepartmental graduate degree program in Logic and Methodology. In his letter to the dean urging its creation, Tarski was already able to describe the University of California as one of the most important centers of such studies in the world. The first Ph.D. in the program was awarded in 1964, and it has been going strong ever since. The campaign for logic on the national and the international scene was carried on in the form of major meetings either totally devoted to logic or in which logic was a