The Yajur Veda[687] associates Rudra with a female deity called Ambikâ or mother, who is however his sister, not his spouse. The earliest forms of the latter seem to connect her with mountains. She is Umâ Haimavatî, the daughter of the Himalayas, and Pârvatî, she of the mountains, and was perhaps originally a sacred peak. In an interesting but brief passage of the Kena Upanishad (III. 12 and IV. 1) Umâ Haimavatî explains to the gods that a being whom they do not know is Brahman. In later times we hear of a similar goddess in the Vindhyas, Mahârânî Vindhyeśvarî, who was connected with human sacrifices and Thugs.[688] Śiva's consort, like her Lord, has many forms classified as white or benignant and black or terrible. Umâ belongs to the former class but the latter (such as Kâlî, Durgâ, Câmundâ, Candâ and Karalâ) are more important.[689] Female deities bearing names like these are worshipped in most parts of India, literally from the Himalaya to Cape Comorin, for the latter name is derived from Kumârî, the Virgin goddess.[690] But the names Śâkta and Śâktism are usually restricted to those sects in Bengal and Assam who worship the Consort of Śiva with the rites prescribed in the Tantras. Śâktism regards the goddess as the active manifestation of the godhead. As such she is styled Śakti, or energy (whence the name Śâkta), and is also identified with Mâyâ, the power which is associated with Brahman and brings the phenomenal world into being. Similar ideas appear in a philosophic form in the Sâṅkhya teaching. Here the soul is masculine and passive: its task is to extricate and isolate itself. But Prakṛiti or Nature is feminine and active: to her is due the evolution of the universe: she involves the soul in actions which cause pain but she also helps the work of liberation.[691] In its fully developed form the doctrine of the Tantras teaches that Śakti is not an emanation or aspect of the deity. There is no distinction between Brahman and Śakti. She is Parabrahman and _parâtparâ_, Supreme of the Supreme.