Glaucon

Glaucon (/ˈɡlɔːkɒn/; Greek: ; c. 445 BC – 4th century BC) son of Ariston, was an ancient Athenian and the philosopher Plato's older brother. He is primarily known as a major conversant with Socrates in the Republic, and the interlocutor during the Allegory of the Cave. He is also referenced briefly in the beginnings of two dialogues of Plato, the Parmenides and Symposium.

Glaucon was the older brother of Plato and, like his brother, was in the inner circle of the young affluent students of Socrates. Although little is known about his life, some information can be extrapolated from Plato's writings and from later Platonic biographers.

He was born in Collytus, just outside Athens, most likely before 445 BC (as he was old enough to serve in the Athenian army during the Battle of Megara, in 424 BC).

His father was Ariston, and his mother was Perictione. According to Diogenes Laërtius, in his Life of Plato, Plato and Glaucon had a sister, Potone, and a brother, Adeimantus. In Plato's dialogue Parmenides, a half-brother, Antiphon, is also mentioned.

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