Surely it is our use of language that somehow determines meaning. But if we try to say how, we must face the fact that only a tiny part of our language, or any human language, is ever used. There are many reasons why a meaningful sentence might never be suited to serve anyone's conversational purposes, and so might go unused. For instance, take length. Even the most abominable stylist will never write a sentence more than, say, a hundred words long. (Never? – Well, hardly ever.) But almost all of the infinitely many meaningful sentences of English, all but a finite minority, are longer than a hundred words. Almost all are longer than a thousand words, almost all are longer than a million words … So almost all sentences have meaning without use.

Years ago, Stephen Schiffer raised the meaning-without-use problem against my own account of use and meaning, which ran as follows. A language L is a function that assigns truth conditions to certain verbal expressions, called the sentences of L; one of them is true in L or false in L according as the truth condition assigned to it by L is satisfied or not. To be truthful in L is to avoid uttering any sentence of L unless it is true in L; to be trusting in L is to expect others to be truthful in L. We (or any population) use L iff, by convention, we are truthful and trusting in L.