Aristotle, Nicomachean Ethics, second edition, translated by Terence Irwin, Indianapolis: Hackett Publishing Co., 1999.
Diogenes Laertius, Lives of Eminent Philosophers, translated by R.D. Hicks. Loeb Classical Library, Cambridge: Harvard University Press, 1991.
Plato, Complete Works, John M. Cooper (ed.), Indianapolis: Hackett Publishing Co., 1997.
Plotinus, Enneads, Vol. I-VI, translated by A.H. Armstrong, Loeb Classical Library, Cambridge: Harvard University Press, 1966-1988.
Plutarch, Moralia, translated by Harold Cherniss, Loeb Classical Library, Vol. XIII, Part II, Cambridge: Harvard University Press, 1993.
Xenophon, Memorabilia and Oeconomicus, translated by E.C. Marchant, Loeb Classical Library, Cambridge: Harvard University Press, 1979.