 In a way, this consequence of the principle seems very plausible, given Aristotle’s idea that it is universals that are definable (Ζ.11, 1036a29). Consider as a definiendum a universal, such as man, and its definiens, rational animal. The parts of this definiens are the universals rational and animal. If these parts are, in turn, definable, then each should be replaced, in the definition of man, with its own definition, and so on. In this way the complete and adequate definition of a universal such as man will contain no parts that are further definable. All proper, or completely analyzed, definitions are ultimately composed of simple terms that are not further definable.