1. Aristotle. 1984. Metaphysics. In The Complete Works of Aristotle: The Revised Oxford Translation, vol. 2, 1552–1728. Translated by W. D. Ross. Edited and revised by Jonathan Barnes, 2 vols. Oxford: Oxford University Press.
2. Augustine. 1992. Confessions. Edited by J. J. O’Donnell, 3 vols. Oxford: Oxford University Press.
3. Bateson, Gregory. 2000a. Steps to An Ecology of Mind. Chicago: Chicago University Press.
4. ———. 2000b. The Effects of Conscious Purpose on Human Adaptation. In Steps, 446–453.
5. ———. 2000d. Form, Substance, Difference. In Steps, 454–472.