This is Volume IV of twelve in the Analytical Psychology Series. Originally published in 1955, experiment in depth set out in this book derives mainly from the work of three men: C. G. Jung, the psychologist; T. S. Eliot, the poet; and A.J. Toynbee, the historian. Each of them, in his own way, has employed what Eliot once termed the 'mythical method'-the exploration of those symbols, visions, idees-forces which, acting powerfully from the unconscious depths, enable men and communities to form new energies, new values and new aims. In the present age the mythical method has been used chiefly by the totalitarian ideologies, for purposes of domination and power. The question examined here is whether and how it can be used to better purpose.