 The idea that we know (even some of) our sensations by acquaintance remains highly controversial. The idea that we know our beliefs or other attitudes by acquaintance is even more controversial. As James (1884) observed, self-knowledge requires more than even direct contact with a mental state: it requires that one properly conceptualize the state, classifying it as e.g. pain or coldness. The greatest challenge for acquaintance accounts is to explain how this conceptualization occurs. In particular, they must show that awareness of a mental state that is direct and immediate can also be an epistemically substantial grasp of the state as a state of a certain kind.