The focus of this dissertation is a special type of moral ignorance: non-culpable ignorance of truths of the form I am obligated to do/not do X. Call ignorance of this type NCFPO ignorance (for Non-Culpable First-Person Obligation ignorance). Many philosophers believe that NCFPO ignorance exists. But whether NCFPO ignorance is possible hangs on the issue of whether a person can be obligated to perform an action that, for good reason, she does not believe that she is obligated to perform-an issue about which philosophers disagree. Is it the case, then, that NCFPO ignorance is possible? And if it is, just how extreme can a person's NCFPO ignorance be? Is it possible for a person to be non-culpably ignorant of all of her moral obligations? If so, under what conditions is this possible? I argue here that NCFPO ignorance is not only possible, but it is possible for a person to be non-culpably ignorant of all of her moral obligations. This conclusion sheds light on several previously unexplored connections between epistemologists' views of external world skepticism and ethicists' views of moral skepticism. It also has implications concerning moral practice, since, as I argue in the dissertation, NCFPO ignorance constitutes an excuse for wrongdoing.