In ancient Greece there existed a group of spiritual practicioners whom scholars have called 'iatromanteis' (medicine men). This is coined from the term 'aitros' (healer). Examples include Pythagoras of Samos, Empedocles of Acragos, Abaris, Aristeas of Proconnesus, Bakis, Epimenides of Crete, and Hermotimos of Clazomenae.
These were reputed to be masters of separating the Soul from the body. The ancient Greeks had a number of ways of referring to such individuals, including,
'Throbates' (spirit/air traveler)
'Cresmologos' (author of oracles)
'Thalmatourgos' (worker of miracles)
The iatromanteis made their journeys into space and other dimensions via a trance technique which they called 'apnous'. This term is usually translated as Catalepsy. Upon the return of the Soul to the body, the medicine man would relate the tale of the flight of Soul and convey any important information or instructions. A number of inquiries have been made about western shamanic experience and tradition. The above information, which is available in The Encyclopedia of Religion, New York, Macmillan; v. 1, p. 436, (Article) Ascension by Ioan Petru Culianu.
The western tradition is focused on the experience of sacred mysteries of direct experience with the principle of order in the universe, usually called 'logos'. A separate shamanic tradition was present in the germanic, celtic, slavic, and finnic countries. However, in the lands around the Mediterranean Sea it seems to have become a part of a larger tradition of gnosis from an early date. In Mesopotamian, Egyptian, Hellenic and Latin spiritual traditions shamanic experience or shamanic ecstasis was one of may tools for initiates of many traditions. The Orphic Pythagorean, Platonic and Gnostic traditions seem to follow this model. Shamans from these lands were part of something that was not centrally focused or defined by shamanic experience. They sought the same experience as those whose unitive visions brought them into contact with divine spirit.
In late Antiquity, among those we know today as Gnostics and NeoPlatonists, descriptions of voyages of Soul into other realms often provided essential details for their respective emerging cosmologies and systems for spiritual liberation.