Epistemic defeat has to do with the lowering, eliminating, or general downgrading of positive epistemic statuses, especially the statuses of being justified or having knowledge. On most accounts of justification, beliefs can be justified even when the property in virtue of which they are justified does not guarantee their truth. That is, justification is fallible. And for any fallibly justified belief, there is always the possibility that further information could come to light, which would render the belief unjustified once the subject becomes aware of it. When a subject becomes aware of such further information, her justification is defeated, and the defeating information (or her awareness of it) is a defeater. Furthermore, according to standard defeasibility analyses of knowledge, roughly, the existence of defeating information for a subject S’s justification for her belief that p is sufficient to prevent S from having knowledge that p, even while S is unaware of the defeating information and she retains justification for her belief. Note that knowledge is sometimes said to be defeasible, and sometimes it is said to be indefeasible. These characterizations of knowledge are compatible. When knowledge is said to be defeasible, the claim is that the justification required for knowledge is fallible, and possibly subject to defeat: roughly, the point is that it is in general possible that S knows that p on the basis of evidence E even if there are possible worlds in which S possesses E (or, there are possible worlds in which S’s belief that p is justified in the same way as in the actual world), and p is false. And it is therefore possible that the addition of some new evidence E′ to E could reduce or eliminate S’s justification for believing p on the basis of E. The addition of E′ to E would also defeat S’s knowledge that p. By contrast, when knowledge is said to be indefeasible, the claim is that if S knows that p, then there is not any actual further true proposition that would defeat S’s justification for her belief if it were conjoined to her evidence. In other words, to say that S’s knowledge that p is defeasible is to say that S can know that p in the actual world even though there are possible worlds in which there exist further facts that could come to light, which would defeat S’s justification for (and knowledge that) p. To say that S’s knowledge that p is indefeasible is to say that there are no such facts in the actual world. In general, if S knows that p in world W then S’s justification cannot be defeated by any facts that obtain in W. Although most contemporary epistemologists are fallibilists about knowledge, the claim that knowledge is indefeasibly justified true belief is compatible with both fallibilism and infallibilism about knowledge.
Una defensa de la solución conceptualista al “problema de la fundamentación” para objetos coincidentes
