According to Sarira Traya, the Doctrine of the Three bodies in Hinduism, the human being is composed of three sariras or "bodies" emanating from Brahman by avidya, "ignorance" or "nescience". They are often equated with the five koshas (sheaths), which cover the atman. The Three Bodies Doctrine is an essential doctrine in Indian philosophy and religion, especially Yoga, Advaita Vedanta and Tantra.