Scepticism and Reliable Belief * By JOSE ZALABARDO

Abstract

Nozick (1981) famously advocated a tracking theory of knowledge according to which S knows that p only if S would not believe p if p were false and S would believe p if p were true. These two modal conditions on knowledge, sensitivity and adherence respectively, seem initially to provide a neat solution to the Gettier problem and the problem about scepticism. For instance, the reason you fail to know there�s a barn in fake barn county despite having a justified true belief is that you would still believe there�s a barn if instead you were looking at one of the many barn facades. And while both conditions are met when it comes to your belief that you have hands, your belief that you are not a handless brain in a vat (BIV) is insensitive, and so you cannot know that you are not a BIV. So, your lack of knowledge of the negation of sceptical hypotheses seems to inflict no damage on your putative knowledge of everyday propositions. So far, so good. The problem with the requirement that sensitivity be a necessary condition on knowledge is twofold. First off, given your knowledge that having hands entails not being a BIV, Nozick�s anti-sceptical strategy implies that knowledge is not invariably closed under known entailment. Secondly, there are intuitive cases of insensitive knowledge. Some of these, including Nozick�s own grandmother case, can be handled by insisting that S sensitively believes p just in case S would not believe p using the same method that S uses in the actual world if p were false. But, as Zalabardo notes, method-relativization of sensitivity fails to deal with all such cases, including Sosa�s (1999) rubbish chute. You drop a rubbish bag down the chute in a high-rise condo. Intuitively, moments later you know that �