Does it make any sense today to look for the intersections between rationality and morals? Were the ancient and medieval philosophies, in which these intersections were present, wrong? And what led to the resolute divorce between these two phenomena? What is the justification for the latter? And is it reasonable? The aim of my article is to provide answers to these questions, which would be based on a systematic study of the relationship between these two phenomena. Thus I go back to the tradition of thought beginning with Socrates and reaching its peak in the philosophy of St. Thomas Aquinas. This tradition was reintroduced into the modern philosophic discourse by Alasdair MacIntyre.