As we saw when we looked at behaviourism, philosophers like Gilbert Ryle argued that it is not necessary to consider the mind as a separate physical substance, as Descartes did. This “ghost in the machine”, as Ryle called it, is totally unnecessary in accounting for the existence of a mind as long as we restrict our definition of mental activity to potentially observable behaviour.

This looks like a good candidate for solving the problem of other minds. For instance look again at the diagram which I used to illustrate Mill’s view.

It is possible to do away with the middle box – the only unobservable part – and so do away with the problem.

Me and others