How did Alfred Tarski contribute to logical semantics?

Alfred Tarski made foundational contributions to logical semantics by developing a rigorous, formal definition of truth for mathematical and logical languages. His work addressed the liar paradox by demonstrating that a consistent definition of truth cannot be formulated within the language itself (the object language) but must instead be constructed in a richer metalanguage.12

Key aspects of his contribution include:

• Truth Conditions and T-sentences: Tarski showed that truth for a formal language can be defined by assigning truth conditions to each sentence. He utilized "T-sentences," which state that a sentence (S) is true if and only if a corresponding statement in the metalanguage holds true (e.g., "Snow is white" is true if and only if snow is white).13
• Satisfaction: He defined truth as a special case of "satisfaction," a relation between the constituents of a sentence and sequences of objects. This allowed for a compositional definition, where the truth of complex formulas is derived from the semantic attributes of their simpler components.32
• Model Theory: Tarski was a pioneer in the development of model theory, providing concepts and methods that remain central to the study of algebraic structures and formal systems.4

Tarski’s work provided the logical foundation for truth-conditional semantics, which later influenced philosophers like Donald Davidson in their efforts to account for linguistic meaning.3