Introduction

Frege's story about indirect contexts – ‘that’ clauses, like ‘Harry believes that’ and ‘Joan said that’ – is widely known and enormously influential. And yet it is only the briefest of sketches. Here is what he says in “On Sense and Reference”:

It is quite elegant, the way he has knitted together the sense/reference distinction and the problem of substitutivity in oblique contexts. But it is not as tight as one might think. For we know what the customary reference of an expression is supposed to be: the customary reference is the thing the word stands for. We also know what the customary sense of an expression is supposed to be: the customary sense is, roughly, the meaning of the expression. So we know what the indirect reference is supposed to be: Frege explicitly identifies the indirect reference with the customary sense. But what is the indirect sense supposed to be?