One of the things that epistemologists worry about is the relation of epistemic support, in virtue of which something gives a subject reason to believe that a proposition is true. While the notion of epistemic support might be accounted for in a variety of ways, for the sake of simplicity in what follows I will assume that what gives a subject reason to believe that a proposition p is true is the possession of a piece of evidence that supports p. We can thus say that evidence for p is a justifier for p, in that it provides the agent with justification to believe that p is true. If justifiers—evidence—provide the epistemic agent with justification, defeaters take justification away from her. Just like justifiers, defeaters have epistemic force, but it is a force that speaks against believing a proposition, rather than in favour of it. For the purposes of this paper, let us understand defeaters as pieces of counterevidence—evidence that speaks against believing a proposition.
˜