Further reading
- Lowell Bair, The Essential Works of Descartes, Bantam, 1966
- James Hillman, The Thought of the Heart and the Soul of the World, Spring, 1982
- R. D. Laing, The Politics of Experience and The Bird of Paradise, Penguin, 1967
- Elmer O'Brien, The Essential Plotinus, Hackett, 1978
- Allan Pease, Body Language, Sheldon Press, 1984
- Ken Wilber, A Brief History of Everything, Gill & Macmillan, 1996