This is the first (and yet unfinished) draft of my contribution to a German anthology on the naturalistic fallacy in philosophy, logic and law. I first explain the two senses of the concept ‘naturalistic fallacy’ in philosophy, distinguishing between (i) G.E. Moore’s claim that it is impossible to define ‘good’, and (ii) David Hume’s suggestion that one cannot deduce ought-conclusions from is-premises. Based on that, I argue that Aristotelian Naturalism does not rest on a naturalistic fallacy in the Humean sense. It should, however, take Moore’s claim more seriously. In order to do so, Aristotle’s idea of ‘good’ as a transcendental term might be helpful.