This Savit_r_i, the sun, is, of course, more than the fiery ball that rises from the sea or over the hills, but nevertheless the real sun serves as a symbol, and it was that symbol which suggested to the suppliant the divine power manifested in the sun. Hence almost everything that could be predicated of the sun was predicated of Savit_r_i also, whatever was true of the sky, Dyaus, fem., was supposed to be true of Dyaus, masc., Zeus or Jupiter also. As early an authority as Kâtyâyana in his Index to the Rig-Veda declared that all the gods invoked in the Vedic hymns can be reduced to three, to Agni, fire and light, on earth, to Vâyu, air, in the atmosphere, and to Sûrya, sun, in the sky, but he adds that all three are in the end meant for one, for Pra_g_âpati, the Lord of creation. And later on he says, that there is only one deity, namely the Great Self, Mahân Âtmâ, and some say that he is the sun, (Sûrya), or that the sun is he. One of the prayers in the Sandhyâvandana begins with Asâv Âdityo Brahma, that Âditya (sun) is Brahman, and in the Taitt. Upanishad, VIII, 8, it is said: “He who dwells in man and he who dwells in the sun, are one and the same.” The same idea may be likewise deduced from the hymns themselves. In X, 158, 1, we read: “May the sun (Sûrya) protect us from the sky, the wind (Vâyu) from mid-air, and fire (Agni) from the earth;” whereas in another hymn, 115, 1, we read: “the Sun is the Self or soul of all that moves and rests.” Here we can clearly watch the gradual transition from the visible sun to the invisible agent of the sun which may have taken centuries to evolve, and if we consider how almost everything on earth is dependent on the sun for its very life, we can understand how a perfectly natural road led from the sun as seen in heaven, to the sun as the highest, the supreme, nay, in the end, as the only deity. This religious and philosophical development of the concept of the sun did not, however, prevent its simultaneous mythological growth. This is the famous Solar Theory, which, no doubt, has been much exaggerated, but which, if properly understood, admits, we know, of cheap cavil, but never of refutation; nay, which, if but rightly understood, has really received more support from its supposed critics than from its originators and supporters. One of the most intelligible names given to the sun was A_s_va, the racer, or Dadhikrâvan or Vâ_g_in, horse. And while at one time the sun was a racer, at another the sun was conceived as approaching men and standing on a golden chariot which was drawn by horses, as in Greek mythology. Thus we read, Rig-Veda I, 35, 2: “The god Savit_r_i (the sun), approaching on the dark-blue sky, sustaining mortals and immortals, comes on his golden chariot, beholding all the worlds.”