Tarski's Hidden Assumption

It is clear that Tarski's T‐scheme, ‘T”p” if and only if p’, does not hold universally. It is not expected to hold, for instance, with ambiguous sentences, or with indexical sentences. Making explicit the circumstances where it does hold, however, is not just logical housekeeping: it turns out to have more radical consequences for the whole approach to Semantics associated with Tarski than has previously been envisaged.