Logical consequence revisited

Tarski’s 1936 paper, “On the concept of logical consequence”, is a rather philosophical, non-technical paper that leaves room for conflicting interpretations. My purpose is to review some important issues that explicitly or implicitly constitute its themes. My discussion contains four sections: (1) terminological and conceptual preliminaries, (2) Tarski’s definition of the concept of logical consequence, (3) Tarski’s discussion of omega-incomplete theories, and (4) concluding remarks concerning the kind of conception that Tarski’s definition was intended to explicate. The third section involves subsidiary issues, such as Tarski’s discussion concerning the distinction between material and formal consequence and the important question of the criterion for distinguishing between logical and non-logical terms.