 “Sharing moral knowledge with oneself” might mean and imply different things. As for the object of knowledge, for example, it might refer to knowledge of one’s own conduct in view of an assessment of it against a certain moral standard, or it might refer to knowledge of moral standards or principles themselves. As for the “self” with whom knowledge is shared, it might mean sharing knowledge with a part of the self, as if we were split into two persons (Sorabji 2014: 12), but it might also mean sharing knowledge with an imaginary witness, such as an ideal observer (for instance a god, an imagined moral model, an impartial spectator). Unfortunately, debates in which appeals to conscience are often made—for example the debate about conscientious objection in health care—are often characterized by a lack of clarity as to what it exactly is that we are talking about when we talk about conscience, and therefore about what exactly people are claiming when they put forward a “conscientious objection” to, for example, abortion. In what sense does abortion violate the conscience of a committed Catholic doctor? And is conscience amenable to reason and public discussion, or are appeals to conscience ultimately based on intuitions and private morality? In what sense is a conscientious choice different from a mere moral preference? The notion of conscience is in need of conceptual clarification.