The rise of the Brahmans into a caste changed the character of the sacrifice by making its due celebration depend more on special knowledge, and by increasing its elaborate mystery. Once the hymn was recognised as an essential element of such an act, the person who could interpret the hymn and explain its effects acquired great importance. And when the explanation of all the various features of the sacrifice was once begun, a wide door was opened to minute ingenuity. It is astonishing to what trifles these priestly directories descend, what explanations are brought from every part of earth and heaven of the most trivial circumstances, and what sacredness is found in the very blades of grass around the altar. Now the effect of such a treatment of ritual is inevitably that the rite itself, the outward mechanical performance, comes to be regarded as important, and that the ethical and religious end which was originally aimed at, is lost sight of. The priest and those he acts for are so intent on the minutiae of their celebration that they forget about the god it is intended for. And as they are quite convinced that the sacrifice, if offered with perfect correctness and with nothing left out, must produce its effect, the sacrifice itself comes to appear as the agent of the desired blessing; the god grows less but the sacrifice grows more. This process, which may be observed wherever ritualism exists, was carried in the period of Brahmanism to its utmost length. In this period the old gods lost the strong hold they had before over the people's mind; men ceased to look for their gods to the sky or to the tempest, and began to look instead to the long ceremonies of the priest or to the hymn he chanted at the altar, or to the austerities he practised. Gods of a new type now make their appearance. As in the Vedic period we saw that Brahmanaspati, lord of prayer, had a place beside Indra and Varuna, so now we see that the supreme deity is named Brahma. The prayer connected with the sacrifice has given its name to the ruler of the universe. Other names for the supreme are also found to be making their way to general use, as the old historical and mythological gods fall into the background, and an abstract divine unity is sought after. Prajapati, lord of creatures, who is little heard of in the hymns, is frequently invoked as the head of all the gods, and a triad of gods is heard of, consisting of Agni, Vayu, Surya, fire, the air, the sun, and summing up the divine energies. The attributes of the gods are personified, and a set of pale abstractions is thus added to the Pantheon; and spirits and goblins not heard of in the hymns, though not therefore necessarily unknown in the former period, make their appearance. These are, perhaps, the gods of the aborigines, who thus revenge themselves, as the religion of the invaders which at first suppressed them loses its earlier vigour. The strong gods retire and weak gods, many and shadowy, and