The question how to turn the principles implicitly governing the concept of truth into an explicit definition (or explication) of the concept hence coalesced with the question how to get a finite grip on the infinity of T-sentences. Tarski's famous and ingenious move was to introduce a new concept, satisfaction, which could be, on the one hand, recursively defined, and which, on the other hand, straightforwardly yielded an explication of truth. A surprising 'by-product' of Tarski's effort to bring truth under control was the breathtaking finding that truth is in a precisely defined sense ineffable, that no non­ trivial language can contain a truth-predicate which would be adequate for the very 4 language . This implied that truth (and consequently semantic concepts to which truth appeared to be reducible) proved itself to be strangely 'language-dependent': we can have a concept of truth- in-L