Wittgenstein is often thought to have challenged the view that assertion is an important theoretical category in a philosophical view of language. One of Wittgenstein’s main themes in the early sections of the Investigations is that philosophy misses important distinctions about the uses of language, distinctions hidden from us by ‘the uniform appearances of words’ (1958: §11). As Wittgenstein goes on to say:
It is like looking into the cabin of a locomotive. We see handles all looking more or less alike. (Naturally, since they are all supposed to be handled.) But one is the handle of a crank which can be moved continuously (it regulates the opening of a valve); another is the handle of a switch, which has only two effective positions, it is either off or on; a third is the handle of a brakelever, the harder one pulls on it, the harder it brakes; a fourth, the handle of a pump: it has an effect only so long as it is moved to and fro. (1958: §12)
Few contemporary philosophers share Wittgenstein’s evident familiarity with the cabin of a steam locomotive and, in general, most of us are increasingly remote from all but the most superficial understanding of the underlying functions of the tools on which we rely. So we are perhaps even more prone to the mistake that Wittgenstein thinks that philosophy makes with respect to language, that of regarding it as one tool rather than many: ‘Think of the tools in a tool-box: there is a hammer, pliers, a saw, a screw-driver, a rule, a glue-pot, glue, nails and screws.— The functions of words are as diverse as the functions of these objects’1 (1958: §11).