Ethical or moral subjectivism, sometimes called individualist ethical subjectivism, is the view that moral truths exist, but they are determined on an individual level.
As a cognitivist approach to subjectivism, ethical subjectivism holds that moral statements can be propositions, but that they describe the attitudes of an individual agent rather than something social, cultural or objectively universal.
According to the ethical subjectivist, all moral statements are true if the person stating them believes them to be true.
Jean-Paul Sartre promoted ethical subjectivism as a form of moral relativism. For Sartre, social conventions are an important part of governing one's conduct, but only one's individual moral identity had any real authenticity as a source of moral truth.