Cropsey, Joseph, "Crito," Plato's World: Man's Place in the Cosmos, Chicago, IL: University of Chicago Press, 1995.

Excerpt:

Crito illuminates a theme that is perhaps best known in the Aristotelean formulation that sets side by side the human being as such and the human being as denizen of a civil society—man and citizen. Though he may claim that man is by nature a political animal, Aristotle knows that man is not by nature a citizen, for he goes on to report the conventional or simply legal qualifications for citizenship of the several regimes. Hobbes, Rousseau, and others will distinguish between natural and civil man.

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