Crito: Crito is a follower of Socrates who tries unsuccessfully to persuade his teacher to escape from prison. When Socrates explains to him why he can't flee his death sentence, Crito concedes, admitting Socrates' logic is valid.

Socrates: Socrates, a fifth century B.C. Athenian philosopher, is the main speaker throughout Crito. Though he is condemned to death by the city of Athens, he abides by the jury's verdict, citing the covenant he has made with the polis. Socrates is the first of three Greek philosophers who revolutionize Western thinking. His younger protégées, Plato and then Aristotle, expand on his ideas about religion, politics and society.