I have been reading Robert Nozick’s Philosophical Explanations (a difficult text indeed) and have a question about his theory of knowledge; specifically, Nozick concedes to the knowledge skeptic that we cannot know, say, if we are a brain in a vat on Alpha Centauri (our experience of the world would be identical, says the skeptic, to what it is now, so we cannot know); but he then also notes that it does not follow that I cannot know, say, that I am typing on my computer. If I understand correctly, Nozick holds that my belief that I am typing tracks the fact that I am typing; I would not have the belief that I am typing if I were not typing. This, however, seems problematic to me; it seems to beg the question, i.e. assume the “fact” that I am typing is indeed a fact. Isn’t this what we precisely do not know according to the skeptic? What if I see a perceptual distortion, for example, a pencil wobbling like rubber when I place it between my thumb and index finger and quickly move it back and forth? My perception says it is “rubbery” but I know this to not be true; this seems to present a problem to what Nozick is suggesting, though I admit I may not understand the argument well enough.