Take any belief of yours – even one about which you feel supremely confident. The Sceptic will ask: why do you think it is true? You might take yourself to have a very good reason to believe what you do. But the sceptic will also want to know why you think that this second thing is true as well. You might offer yet a third reason for believing that, but the sceptic won't stop. He will want, again, to know why you believe that third thing. How will you choose to answer the sceptic's constant questioning? You might just keep going on, offering yet more and more reasons every time the sceptic questions you. Or you might argue in a circle, so that you defend your original belief by an argument which eventually appeals again to that very belief. Or you might argue that your original belief can eventually be defended by appeal to a set of assumptions for which you do not have any further reasons. But are any of those options really acceptable, or should you give up your original belief? If the latter, then since the sceptic could question any of your beliefs in this way, does that mean that you should give up all of your beliefs? Are you open to blame and criticism just for believing anything at all?
The Pyrrhonian sceptic tries to convince us that the answers to these questions are “yes”. In this work, I explicate the sceptical strategy in detail and consider philosophical attempts to evade its dire conclusion. My development of Scepticism draws on the ideas of Sextus and three of his scholars, Barnes, Bailey and Machuca, as well as BonJour and Oakley.
A number of philosophers have criticized Scepticism on the grounds that it presupposes a nonordinary definition of “knowledge”. The sceptic tries to show that our common-sense belief that we know all sorts of things about the world is really a giant error, but the only way he manages to do it, according to these philosophers, is by starting with a definition of “knowledge” vastly removed from our usual one. This strategy is the dominant way of criticizing Scepticism in contemporary epistemology. It is deployed by John Greco, Alvin Goldman, Mark Kaplan and many others. Against these philosophers, I urge that the sceptic's using the word “know” in a non-ordinary way does not harm the substance of his arguments at all.
A number of philosophers have argued that the sceptic's standards for right or justified belief should be rejected. I argue that the standard which the Pyrrhonian lays down is not at all ridiculous. All he asks of us is that we have some reason, no matter how weak, for believing that P rather than -P – a reason which might convince someone who did not already believe that P. And so the sceptic lays down a standard which it may be very difficult to give up. What's more, I argue, by discussing the views of Michael Williams and Michael Huemer, that it is far from clear that there is anything in the neighbourhood that is particularly plausible as an ethics of belief.
These two broad anti-sceptical gambits are the currently dominant ones. In showing them to be unsatisfactory, I show that the sceptic still has us firmly in his net.