Vishnu has altered immensely since last we met him. First, after an extraordinary change in his own character, he has been identified with Narayana, and then both of them have been equated with Krishna. The development is so portentous that it calls for a little study.
We have seen that in the Vedas Vishnu appears to be, and in the Brahmanas certainly is, the embodied Spirit of the Sacrifice, and that ritual mysticism has invented for him a supreme home in the highest heaven. But in the Epics he has developed into a radiant and gracious figure of ideal divinity, an almighty saviour with a long record of holy works for the salvation of mankind, a god who delights in moral goodness as well as in ritual propriety, and who from time to time incarnates himself in human or animal form so as to maintain the order of righteousness. Symbolism has further endowed him with a consort, the goddess Sri or Lakshmi, typifying fortune; sometimes also he is represented with another wife, the Earth-goddess. The divine hawk or kite Garuda, who seems to have been originally the same as the eagle who in the Rigvedic legend carried off the soma for Indra, has been pressed into his service; he now rides on Garuda, and bears his figure upon his banner. I have already suggested a possible explanation of this evolution (above, p. 41): owing to his close association with Indra, the most truly popular of Rigvedic deities, the laic imagination transfused some of the live blood of Indra into the veins of the priestly abstraction Vishnu. To the plain man Indra was very real; and as he frequently heard tales of Indra being aided in his exploits by Vishnu, he came to regard Vishnu as a very present helper in trouble. The friend of Indra became the friend of mankind. The post of Indra had already been fixed for him by the theologians; but the functions of Vishnu, outside the rituals, were still somewhat vaguely defined, and were capable of considerable expansion. Here was a great opportunity for those souls who were seeking for a supreme god of grace, and were not satisfied to find him in Siva; and they made full use of it, and wholly transformed the personality of Vishnu.
One of the stages in this transformation was the absorption of Narayana in Vishnu. Narayana was originally a god of a different kind. The earliest reference to him is in a Brahmana which calls him Purusha Narayana, which means that it regards him as being the same as the Universal Spirit which creates from itself the cosmos; it relates that Purusha Narayana pervaded the whole of nature (SB. XII. iii. 4, 1), and that he made himself omnipresent and supreme over all beings by performing a _pañcha-ratra sattra_, or series of sacrifices lasting over five days (ib. XIII. vi. 1, 1). Somewhat later we find prayers addressed to Narayana, Vasudeva, and Vishnu as three phases of the same god (Taitt. Aran. X. i. 6). But was Narayana in origin merely a variety of the Vedic Purusha or our old acquaintance Prajapati? His name must give us pause. The most simple explanation of it is that it is a family name: as Karshnayana means a member of the Krishna-family and Ranayana a man belonging to the family of Rana, so Narayana would naturally denote a person of the family of Nara. But Nara itself signifies a _man_: is the etymology therefore reduced to absurdity? Not at all: Nara is also used as a proper name, as we shall see.[21] Probably the name really means what naturally it would seem to mean, "a man of the Nara family"; that Narayana was originally a divine or deified saint, a _rishi_, as the Hindus would call him; and that somehow he became identified with Vishnu and the Universal Spirit.