  So an important element of McDowell’s disjunctive approach is his opposition to a certain view of self-knowledge. (See especially McDowell 1987.) According to the view he opposes, although your ability to tell how things are in the world by looking is fallible, your ability to tell how things are with you subjectively is infallible, in the following sense: the truth about how things are with you subjectively is infallibly accessible to your capacity to acquire knowledge on such matters.This picture of self-knowledge is incompatible with the disjunctive account of experience that McDowell recommends. According to that disjunctive account when you have an experience, you can know, independently of whether you know that you are hallucinating, that it appears to you that such and such is the case. However, its appearing to you that a such and such is the case can be either a situation in which a fact in the environment is being made perceptually manifest to you, or a situation that involves a mere appearance, and you cannot know which disjunct obtains independently of knowing whether you are hallucinating. According to McDowell, when a fact is made perceptually manifest to you, the obtaining of the fact is not “blankly external to your subjectivity”. The resultant view is incompatible with the claim that all of the truths about how things are with you subjectively are infallibly accessible to you. For if all of the truths about things are with you subjectively were infallibly accessible to you, your capacity to know whether or not you were hallucinating would also be infallible.