The indefinability of truth in the “Wahrheitsbegriff” Original Research Article

Contrary to what often seems to be the implicit belief, Tarskiʹs 1933 version of the theorem on the indefinability of truth did not mention semantic notions, either defined or intuitive. I state this version in a somewhat modernized form and explain briefly the self-imposed mathematico-philosophical constraints that led Tarski to formulate it as he did. I also point out that close attention to its content suggests a refined view of the exact contrast between Tarskiʹs achievement and Gödelʹs achievement in his earlier discovery of another version of the result.