In so far as Yoga represents a reaction against ritualism and scholastic speculation, it adheres to the aboriginal tradition and stands against the Indo-European religious heritage. We have, in fact, frequently had occasion to stress the resistance to the various forms of Yoga on the part of orthodox circles—that is, the tributaries of the Indo-European tradition. As we have pointed out, the absence of the Yoga complex from other Indo-European groups confirms the supposition that this technique is a creation of the Asian continent, of the Indian soil. If we are right in connecting the origins of yogic asceticism with the protohistorical religion of the Indus, we may justifiably conclude that in it we have an archaic form of mystical experience that disappeared from everywhere else. For Yoga cannot be classed among the countless varieties of primitive mysticism to which the term shamanism is commonly applied. Yoga is not a technique of ecstasy; on the contrary, it attempts to realize absolute concentration in order to attain enstasis. In the universal history of mysticism, classic Yoga occupies a place of its own, and one that is difficult to define. It represents a living fossil, a modality of archaic spirituality that has survived nowhere else.

From Mircea Eliade’s Yoga: Immortality and Freedom, Princeton and Oxford: Princeton University Press, 2009 (first published in 1954), p. 361.