Abstract: An extended transcendental argument for moral realism is given cast in terms of an “argument from error”. This is distinguished from an argument from moral phenomenology because the errors under consideration are those that go undetected despite our confidence of their existence. First person error is focused upon in particular as is the human condition in general. The argument establishes a presumption in favor of moral realism, not a conclusive proof. A theory of moral goodness is needed, and a sketch of the ontological, epistemological, semantic, and psychological questions any such theory must answer is given.

Keywords: argument from error, first person error, human condition, moral phenomenology, moral realism, transcendental argument,