In the last chapter we examined the philosophical theories of a number of thinkers whom the textbooks group together under the title of rationalists. We now come to a group of philosophers, most of them English, who attack the problem of scepticism from a somewhat different angle. For the sake of convenience they have been labelled empiricists. What chiefly concerns us is the general problem which they are attacking, and in particular the fact that, in common with the rationalists, they assume to begin with the mutual externality of the world of mind and the world of nature. It will be recalled that in Part I we referred on more than one occasion to the theories of these thinkers, above all, those of Berkeley. Our object in the present chapter is to show how, in spite of apparent divergences, the metaphysical background to their work is the same.