In ancient Greece, a common method of searching for divine wisdom was to descend into caves or underground chambers. Entering caves appears persistently as a major requirement for prophecy-giving, both in established cults and in the activities of individual seers. Underground sojourns recur in the activities of several early Greek sages and philosophers, such as Epimenides, Pythagoras, and Parmenides. Mystery initiation comprise rites located in caves or dark chambers. The aim shared by sages, seers, and initiates was their quest for the hidden truth, which they attained as revelation or vision. Exploring the reasons for the predilection for caves in the search for ultimate truth, Yulia Ustinova juxtaposes ancient testimonies with the results of modern neuroscience. This approach, new in Classical Studies, enables an examination of the consciousness of people who were engaged in the vision quest. Caves and closed spaces create conditions of sensory deprivation and can be instrument in attaining altered states of consciousness, ranging from intense contemplation to visions and sensations of illumination.

Ustinova argues that the fundamental reason for locating the activities of the gods' intermediaries in caves was the need to attain divine inspiration, that is, to cultivate mental imagery. She regards the cave experiences of the Greeks as culturally patterned responses to isolation in closed spaces, which result from the inborn biological capability of the human brain and have been enhanced by age-old techniques for manipulating consciousness. Book jacket.