I will argue that internalism about justification entails the apparently absurd conclusion that it is possible to know specific facts about the external world-for example, that there is a tree in the quad-on the basis of introspection and a priori reflection. After a brief characterization of internalism (</n>1), I will set out the problem (</n>2). I will then discuss three replies: one that denies the form of doxastic voluntarism involved in the problem (</n>3), one that denies that knowledge of higher-order facts about justification can justify corresponding first-order beliefs (</n>4), and, finally, one that involves biting the bullet (</n>5). I will argue that each reply fails.