 Some arguments for philosophical skepticism target knowledge directly, not concerning themselves with justification. For instance, some argue that we do not know certain propositions because our beliefs in them are not sensitive (in a sense to be explained below), and they claim that sensitivity is a condition on knowledge—but perhaps not on justified belief. We will examine the bearing of the sensitivity condition on skeptical arguments assuming that it applies to justification. But even if an argument for philosophical skepticism targets our knowledge in a certain area while remaining silent about whether we have justified beliefs in that area, that argument will still indirectly target our justification as well. For, if the argument succeeds, then it provides us with knowledge (or at least justified belief) that we do not know a certain proposition p. And it is plausible to hold that if we know (or justifiably believe) that we do not know a proposition p, then we are not even justified in believing p.