This collection includes most of Cicero’s purely philosophical (without any mixture of politics) treatises, the texts of which, fortunately for us, have been preserved in their entirety or with very few omissions. Written in the traditional form of dialogues or collections of letters in Antiquity (the conventional “addressee” of which in this case is Cicero’s son Mark), they fully express the unbending, almost Puritan moral and ethical principles of the author - the first in the galaxy of great geniuses of the Roman Stoic tradition, which continued and in many ways changed Greek stoicism.