The composition of this anthology probably extended over several centuries and comprised a period of lively mental growth. It is therefore natural that it should represent stages of religious development which are not contemporaneous. But though thought is active and exuberant in these poems they are not altogether an intellectual outburst excited by the successful advance into India. The calm of settlement as well as the fire of conquest have left their mark on them and during the period of composition religion grew more boldly speculative but also more sedentary, formal and meticulous. The earliest hymns bear traces of quasi-nomadic life, but the writers are no longer nomads. They follow agriculture as well as pasturage, but they are still contending with the aborigines: still expanding and moving on. They mention no states or capitals: they revere rivers and mountains but have no shrines to serve as religious centres, as repositories and factories of tradition. Legends and precepts have of course come down from earlier generations, but are not very definite or cogent: the stories of ancient sages and warriors are vague and wanting in individual colour. 2 The absence of sculpture and painting explains much in the character of the Vedic deities. The hymn-writers were devout and imaginative, not content to revere some undescribed being in the sky, but full of mythology, metaphor and poetry and continually singling out new powers for worship. Among many races the conceptions thus evolved acquire solidity and permanence by the aid of art. An image stereotypes a deity, worshippers from other districts can see it and it remains from generation to generation as a conservative and unifying force. Even a stone may have something of the same effect, for it connects the deity with the events, rites and ideas of a locality. But the earliest stratum of Vedic religion is worship of the powers of nature—such as the Sun, the Sky, the Dawn, the Fire—which are personified but not localized or depicted. Their attributes do not depend at all on art, not much on local or tribal custom but chiefly on imagination and poetry, and as this poetry was not united in one collection until a later period, a bard was under no obligation to conform to the standards of his fellows and probably many bards sang without knowing of one another's existence.