WHAT IS IT TO UNDERSTAND A SENTENCE? Dummett and the Acquisition Argument
DUMMETT AND THE ACQUISITION ARGUMENT We have seen that a number of arguments have been put forward for one or another kind of verifiability criterion. From Hume, the early Wittgenstein, and the logical positivists, we have the argument that if one wants to understand an unclear sentence, one ought to break it down into its constituents and match those constituents with sensory impressions. If there are no such impressions, the sentence is obscure; it has no clear meaning. From the later Wittgenstein, we can extract another semantic argument: meaning is use and so there must be some ability which one has if one understands a statement. We have also from the later Wittgenstein and from Neurath the thought that the maintenance of the ‘is right/seems right’ distinction requires a verificationist criterion. This is not a position primarily about meaning, but rather, one about what must be the case if we are to make sense of objectivity. From Peirce we can take, first, the semantic point that if a hypothesis lacks consequences, it lacks a dimension we would have had to have got right were we to have a comprehensive understanding of it. And second, we can take the point that if a hypothesis is to be useful or to play a role in one inquiry or another, there must be something we can expect if it is true and something we can expect if it is false.