The author is seeking to explain the underlying idea of the Vedic religion; he thinks that the key to this enterprise is to be found in its cosmogony; therefore, he concerns himself with the mythology of the origin of the universe. In the beginning there was only water, which bore in itself the germ of life; and then an unformed clod of earth rose to the surface, where it floated about; but this state of undifferentiated unity came to a sudden end by the second stage of cosmogony. It started with the birth of the god Indra, outside the primeval world. The author of the present paper holds that the function of the myth of Indra is limited to the creation of the dualist world in which good and light are counterbalanced by evil and darkness. The article, then, deals with war between Asuras, the gods of the primordial world, and the Devas who are headed by Indra; this symbolizes the dualism which has entered into the world of the Vedic gods. The article finally points out the universal periods and the destruction of the universe.