The Saktas, as we have seen, are worshippers of the _sakti_, or the female principle as a primary factor in the creation and reproduction of the universe. And as each of the principal gods is supposed to have associated with him his own particular _sakti_, as an indispensable complement enabling him to properly perform his cosmic functions, adherents of this persuasion might be expected to be recruited from all sects. To a certain extent this is indeed the case; but though Vaishnavism, and especially the Krishna creed, with its luxuriant growth of erotic legends, might have seemed peculiarly favourable to a development in this direction, it is practically only in connexion with the Saiva system that an independent cult of the female principle has been developed; whilst in other sects--and, indeed, in the ordinary Saiva cult as well--such worship, even where it is at all prominent, is combined with, and subordinated to, that of the male principle. What has made this cult attach itself more especially to the Saiva creed is doubtless the character of Siva as the type of reproductive power, in addition to his function as destroyer which, as we shall see, is likewise reflected in some of the forms of his Sakti. The theory of the god and his Sakti as cosmic principles is perhaps already foreshadowed in the Vedic couple of Heaven and Earth, whilst in the speculative treatises of the later Vedic period, as well as in the post-Vedic Brahmanical writings, the assumption of the self-existent being dividing himself into a male and a female half usually forms the starting-point of cosmic evolution.[7] In the later Saiva mythology this theory finds its artistic representation in Siva's androgynous form of Ardha-narisa, or "half-woman-lord," typifying the union of the male and female energies; the male half in this form of the deity occupying the right-hand, and the female the left-hand side. In accordance with this type of productive energy, the Saktas divide themselves into two distinct groups, according to whether they attach the greater importance to the male or to the female principle; viz. the _Dakshinacharis_, or "right-hand-observers" (also called _Dak-shina-margis_, or followers "of the right-hand path"), and the _Vamacharis_, or "left-hand-observers" (or _Vama-margis_, followers "of the left path"). Though some of the Puranas, the chief repositories of sectarian doctrines, enter largely into Sakta topics, it is only in the numerous Tantras that these are fully and systematically developed. In these works, almost invariably composed in the form of a colloquy, Siva, as a rule, in answer to questions asked by his consort Parvati, unfolds the mysteries of this occult creed.