Eugen Fischer

A certain orthodoxy has it that understanding is essentially computational: that information about what a sentence means is something that may be generated by means of a derivational process from information about the significance of the sentences constituent parts and of the ways in which they are put together. And that it is therefore fruitful to study formal theories acceptable as compositional theories of meaning for natural languages: theories that deliver for each sentence of their object-language a theorem acceptable as statement of its meaning and derivable from axioms characterizing subsentential expressions and operations forming that sentence. This paper is to show that there is something deeply wrong with these ideas, namely that they are based on a certain confusion about ascriptions of semantic knowledge. The paper is to make this point by considering a semantic theorist who has explicit knowledge of a theory of truth for L. And by showing that all the theorist needs to have knowledge of to understand the sentences of L are these axioms -- that the derivation of T-theorems is epistemically redundant. And that this doesnt change when we turn from explicit to what has been called tacit knowledge.