It is good, then, to remember four options in epistemology (the theory of knowledge). There is rational foundationalism, as attempted by Descartes. There is natural foundationalism, as attempted in Hume. There is coherentism. And brooding over all of them, there is scepticism, or the view that there is no knowledge. Each of these has had distinguished defenders. Whichever the reader prefers, he or she will find good philosophical company.

