When Thrasymachus has been silenced, the two principal respondents, Glaucon and Adeimantus, appear on the scene: here, as in Greek tragedy (compare Introd. to “Phaedo”), three actors are introduced. At first sight the two sons of Ariston may seem to wear a family likeness, like the two friends Simmias and Cebes in the “Phaedo.” But on a nearer examination of them the similarity vanishes, and they are seen to be distinct characters. Glaucon is the impetuous youth who can “just never have enough of fechting” (compare the character of him in Xenophon Memorabilia III 6); the man of pleasure who is acquainted with the mysteries of love (V 474 D); the “juvenis qui gaudet canibus,” and who improves the breed of animals (V 459 A); the lover of art and music (III 398 D, E) who has all the experiences of youthful life. He is full of quickness and penetration, piercing easily below the clumsy platitudes of Thrasymachus to the real difficulty; he turns out to the light the seamy side of human life, and yet does not lose faith in the just and true. It is Glaucon who seizes what may be termed the ludicrous relation of the philosopher to the world, to whom a state of simplicity is “a city of pigs,” who is always prepared with a jest (III 398 C, 407 A; V 450, 451, 468 C; VI 509 C; IX 586) when the argument offers him an opportunity, and who is ever ready to second the humour of Socrates and to appreciate the ridiculous, whether in the connoisseurs of music (VII 531 A), or in the lovers of theatricals (V 475 D), or in the fantastic behaviour of the citizens of democracy (VIII 557 following). His weaknesses are several times alluded to by Socrates (III 402 E; V 474 D, 475 E), who, however, will not allow him to be attacked by his brother Adeimantus (VIII 548 D, E). He is a soldier, and, like Adeimantus, has been distinguished at the battle of Megara (368 A, anno 456?) … The character of Adeimantus is deeper and graver, and the profounder objections are commonly put into his mouth. Glaucon is more demonstrative, and generally opens the game. Adeimantus pursues the argument further. Glaucon has more of the liveliness and quick sympathy of youth; Adeimantus has the maturer judgment of a grown-up man of the world. In the second book, when Glaucon insists that justice and injustice shall be considered without regard to their consequences, Adeimantus remarks that they are regarded by mankind in general only for the sake of their consequences; and in a similar vein of reflection he urges at the beginning of the fourth book that Socrates fails in making his citizens happy, and is answered that happiness is not the first but the second thing, not the direct aim but the indirect consequence of the good government of a State. In the discussion about religion and mythology, Adeimantus is the respondent (III 376–398), but Glaucon breaks in with a slight jest, and carries on the conversation in a lighter tone about music
