Whilst it is difficult to say for certain whether Wittgenstein’s views are fundamentally behaviourist, they do seem to be open to similar objections. The most important of these is that the way that someone behaves is no guarantee of their mental state – I may express my being in pain differently to you without being mad or dysfunctional in any other way.

Another criticism is that the problem of other minds seems to be untouched. It is all very well to say that language and meaning are to some extent public, but this does not bring us any closer to establishing some criterion for the presence of mind in others. This is because even though others seem to behave as if they are conscious in the same way as we are, we cannot know what it is like to be them. So, in the end, the problem of other minds seems to come down to the problem of consciousness.