Aristotle seeks to resolve the problems raised in Posterior Analytics B.3–7 by arguing that our practices of definition and explanation are interdependent. It is not possible to define kinds without appeal to their causal structure, nor is it possible to single out the relevant causal structure without appeal to what is required for good definition. This is why Aristotle holds that the answer to the questions, ‘What is F?’ and ‘Why is F as it is?’ are the same. Neither definition nor explanation can be completed without assistance from the other.
Keywords: Aristotle, definition, demonstration, explanation, natural kinds, Posterior Analytics