In this paper the author summarizes the main contentions made in his new book Abitudine e saggezza. Aristotele dall’Etica Eudemia all’Etica Nicomachea. In the Eudemian Ethics Aristotle makes moral virtue as the joint effect of reason and the gifts of nature, but in the Nicomachean Ethics, on the contrary, he does not even name nature and sees virtue as the product of habits and education. On this very point the NE quotes and praises Plato’s Laws, which Aristotle did not know when writing the EE. It seems clear, then, that in the interval between the two Ethics he had known Plato’s last work.