In his seminal work “The Concept of Truth in Formalized Languages” (1933), Alfred Tarski showed how to construct a formally correct and materially adequate definition of true sentence for certain formalized languages. These results have, eventually, been accepted and applauded by philosophers and logicians nearly in unison. Its Postscript, written two years later, however, has given rise to a considerable amount of controversy. There is an ongoing debate on what Tarski really said in the postscript. These discussions often regard Tarski as putatively changing his logical framework from type theory to set
In what follows, we will compare the original results with those presented two years later. After a brief outline of Carnap’s program in The Logical Syntax of Language we will determine its significance for Tarski’s final results.
Volume 3.10 of The Journal for the History of Analytical Philosophy has been published featuring an article by Monika Gruber entitled “Carnap’s Contribution to Tarski’s Truth”. Here is an abstract: