Alfred Tarski Quotes on Truth
Alfred Tarski's The Concept of Truth in Formalized Languages (1933) gave twentieth-century philosophy of language its founding mathematically rigorous definition of truth for a wide class of formal languages. The famous T-schema — the requirement that any adequate truth-definition entail every instance of the form "S is true if and only if p" (where S names the sentence and p translates it) — supplies the criterion of adequacy, and the construction shows that a formally satisfactory truth-predicate for a given object language can be given in a metalanguage of greater expressive power. Tarski's results have shaped every subsequent analytic discussion of truth, including the deflationary, correspondence, and inflationary positions that defined the late-twentieth-century literature.
Quotes
-
Attributed to Alfred Tarski:
“Snow is white if and only if snow is white.”
-
Attributed to Alfred Tarski:
“Truth in a formalized language can be defined by recursion on the structure of its sentences.”
-
Attributed to Alfred Tarski:
“Logic must distinguish object language from metalanguage to escape the liar.”
-
Attributed to Alfred Tarski:
“A theory may admit several non-isomorphic models, each as legitimate as the others.”
-
Attributed to Alfred Tarski:
“Decidability is the dream and rarely the reality of formal systems.”
-
“The Concept of Truth in Formalized Languages" (1931) in Logic, Semantics, Metamathematics: Papers from 1923 to 1938 (1956) Tr. J. H. Woodger.”
The present article is almost wholly devoted to a single problem— the definition of truth . Its task is to construct—with reference to a given language— a materially adequate and formally correct definition of the term 'true sentence' . This problem, which belongs to the classical problems of philosophy, raises considerable difficulties. For although the meaning of the term 'true sentence' in coll