Abstract
Friendship is a notion that runs through the thought of different ancient philosophers and has the peculiar characteristic of being held in high esteem almost unanimously by all. Although there are earlier precedents, for Socrates friendship takes on great importance and his disciple Plato provides deep reflections on the subject, linking friendship with transcendence. However, the pages of Aristotle's 'Nicomachean Ethics' on this subject are undoubtedly the most influential for posterity. For him, friendship has many variants, although he privileges over all of them friendship between equals and founded on ethical character. Only complete moral integrity guarantees that the love between friends consists of a genuine appreciation for the person of the other and not for something different from it. After Aristotle, Cicero's treatise 'Lellius' or 'On Friendship' stands out. Despite taking up several appreciations of Aristotle, Cicero is original and corrects some of his ideas, giving priority to the strength of mutual love over the preconditions of friends. Moreover, he gives a prominent place to trust ('fides') in their relationship. Finally, Seneca frames friendship within his ethical conception, subordinating love for the friend to the moral development of the philosopher.