The yoga that we see in the Vedas and the principal Upanishads belongs to pre-historic times, and it is only because we have available to us the relevant texts connected with the yoga of these times that we are in a position to ascertain the knowledge related to this yoga and its . development. It cannot be supposed, however, that yoga developed only in the Vedas and the Upanishads. There was, indeed, yoga and yogic knowledge in ancient Egypt,1 ancient Greece, ancient Chaldea, ancient China and ancient Persia as also elsewhere as in ancient Mayan civilization. In ancient Greece, there was a religion of which we have glimpses through the Homeric poems2 where the Olympian Gods were described, and through the earlier, myths that were prevalent in those ancient times.
In Gilbert Murray's 'Five Stages of Greek Religion',3 we have a systematic account, and there is also a good account of Greek religion in J.E. Harrison's 'Prolegomena of the Study of Greek Religion'.4 The Greek religion was not connected only with the Olympians but also with Dionysius or Bacchus, who was originally a Thracian god. The worship of Dionysius in due course of time developed a spiritualized form, and this form is attributed to Orpheus. It is maintained that Orphic doctrines contained much that seems to have its first source in Egypt. The Orphics believed in the transmigration of souls; they also maintained that the soul