The religious life prescribed in the Tantras[711] commences with initiation and requires the supervision of the Guru. The object of it is _Siddhi_ or success, the highest form of which is spiritual perfection. _Siddhi_ is produced by _Sâdhana_, or that method of training the physical and psychic faculties which realizes their potentialities. Tantric training assumes a certain constitution of the universe and the repetition in miniature of this constitution in the human body which contains various nervous centres and subtle channels for the passage of energy unknown to vulgar anatomy. Thus the Śakti who pervades the universe is also present in the body as Kuṇḍalinî, a serpentine coil of energy, and it is part of Sâdhana to arouse this energy and make it mount from the lower to the higher centres. Kuṇḍalinî is also present in sounds and in letters. Hence if different parts of the body are touched to the accompaniment of appropriate mantras (which rite is called nyâsa) the various Śaktis are made to dwell in the human frame in suitable positions. The Tantras recognize that human beings are not equal and that codes and rituals must vary according to temperament and capacity. Three conditions of men, called the animal, heroic and divine,[712] are often mentioned and are said to characterize three periods of life--youth, manhood and age, or three classes of mankind, non-tantrists, ordinary tantrists, and adepts. These three conditions clearly correspond to the three Guṇas. Also men, or rather Hindus, belong to one of seven groups, or stages, according to the religious practices which it is best for them to follow. Śâktists apparently demur[713] to the statement commonly made by Indians as well as by Europeans that they are divided into two sects the Dakshiṇâcârins, or right-hand worshippers, whose ritual is public and decent, and the Vâmâcârins who meet to engage in secret but admittedly immoral orgies. But for practical purposes the division is just, although it must not be supposed that Dakshiṇâcârins necessarily condemn the secret worship. They may consider it as good for others but not for themselves. Śâktists apparently would prefer to state the matter thus. There are seven stages of religion. First come Vedic, Vishnuite and Śivaite worship, all three inferior, and then Dakshiṇâcâra, interpreted as meaning favourable worship, that is favourable to the accomplishment of higher purposes, because the worshipper now begins to understand the nature of Devî, the great goddess. These four kinds of worship are all said to belong to _pravritti_ or active life. The other three, considered to be higher, require a special initiation and belong to _nivritti_, the path of return in which passion and activity are suppressed.[714] And here is propounded the doctrine that passion can be destroyed and exhausted by passion,[715] that is to say that the impulses of eating, drinking and sexual intercourse are best subjugated by indulging them.