I define ‘philosophical scepticism’ as the view that philosophers do not and cannot know many of the substantive philosophical claims that they make or implicitly assume. I argue for philosophical scepticism via the ‘methodology challenge’ and the ‘disagreement challenge’. I claim that the right response to philosophical scepticism is to abandon the view that philosophy aims at knowledge, and (borrowing from David Lewis) to replace it with a more modest aim: that of finding ‘equilibria’ that ‘can withstand examination’. Finally, I (...) consider what our attitude to our own philosophical theses should be. (shrink)