ABSTRACT
This chapter considers three skeptical problems that face empiricism: the problem of the external world, the problem of justifying basic sources of empirical knowledge on empiricist principles and the more general problem of showing that our categories correspond to reality. Critics often argue that empiricism cannot account for obvious cases of knowledge and so implies skepticism. We can then distinguish four doctrines: fallibilism, skepticism, and their negations, infallibilism and what we might label common-sensism. One way empiricists have done this has been to offer metaphysical alternatives to representative realism, which reduce physical objects to sense data, which are clearly within our experience. The metaphysical theories empiricists have offered to solve the problem are phenomenalism and idealism. Whereas phenomenalism solves the problem by collapsing the data-object dualism to sense data, direct realism collapses it by claiming that there are no sense data.
