He is introduced by Cicero as an interlocutor in the De oratore and De natura deorum (iii.), as a supporter of the principles of the New Academy.
A special interest attaches to the dialogues written after the manner of Plato but with Aristotle as principal interlocutor; and some of these, e.g.
In the first of his Dialogues (fair models of Cicero), Severus puts into the mouth of an interlocutor (Posthumianus) a pleasing description of the life of coenobites and solitaries in the deserts bordering on Egypt.
The judgment of Severus himself is no doubt that which he puts in the mouth of his interlocutor Posthumianus: "I am astonished that one and the same man could have so far differed from himself that in the approved portion of his works he has no equal since the apostles, while in that portion for which he is justly blamed it is proved that no man has committed more unseemly errors."
In 633 he was one of the party of Sophronius of Jerusalem (the chief original opponent of the Monothelites) at the council of Alexandria; and in 645 he was again in Africa, when he held in presence of the governor and a number of bishops the disputation with Pyrrhus, the deposed and banished patriarch of Constantinople, which resulted in the (temporary) conversion of his interlocutor to the Dyothelite view.
It brings in the choice of an interlocutor at each stage, and so depends on a concession for what it should prove.'
Ananda entered the Order in the second year of the Buddha's ministry, and became one of his personal attendants, accompanying him on most of his wanderings and being the interlocutor in many of the recorded dialogues.
Pointing out that the sophists of that dialogue " profess Eis ap€riffs E7rt,u XELav 7rporpNiaL by means of dialogue," that ' they challenge the interlocutor inr w Xoyov," that " their examples are drawn from common objects and vulgar trades," that " they maintain positions that we know to have been held by Megarians and Cynics," he infers that " what we have here presented to us as ' sophistic ' is neither more nor less than a caricature of the Megarian logic "; and further, on the ground that " the whole conception of Socrates and his effect on his contemporaries, as all authorities combine to represent it, requires us to assume that his manner of discourse was quite novel, that no one before had systematically attempted to show men their ignorance of what they believed themselves to know," he is " disposed to think that the art of disputation which is ascribed to sophists in the Euthydemus and the Sophistes (and exhaustively analysed by Aristotle in the HEpi originated entirely with Socrates, and that he is altogether responsible for the form at least of this second species of sophistic."