Three Bodies Doctrine

According to Sarira Traya, the Doctrine of the Three bodies in Hinduism, the human being is composed of three shariras 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.
The Three Bodies.
Karana sarira - causal body.
"Karana sarira" or the causal body is merely the cause or seed of the subtle body and the gross body. It has no other function than being the seed of the subtle and the gross body. It is "nirvikalpa rupam", "undifferentiated form". It originates with "avidya", "ignorance" or "nescience" of the real identity of the atman, instead giving birth to the notion of "jiva".
Swami Sivananda characterizes the causal body as "The beginningless ignorance that is indescribable". Siddharameshwar Maharaj, the guru of Nisargadatta Maharaj, also describes the causal body as characterized by "emptiness", "ignorance", and "darkness". In the search for the "I am", this is a state where there is nothing to hold on to anymore.
Ramanuja concludes that it is at this stage that consummation of the atman with the Paramatman is reached and the search for the highest Purusa, i.e., of Ishvara, ends.
According to other philosophical schools, the causal body is not the "atman", because it also has a beginning and an end and is subject to modification. Shankara, not seeking a personal god, goes beyond "Anandamaya Kosha" in search of the transcendent Brahman.
The Indian tradition identifies it with the "Anandamaya kosha", and the deep sleep state, where "buddhi" becomes dormant and all concepts of time fail, although there are differences between these three descriptions.
The causal body is considered as the most complex of the three bodies. It contains the impressions of experience, which results from past experience.
Sukshma sarira - subtle body.
"Sukshma sarira" or the subtle body is the body of the mind and the vital energies, which keep the physical body alive. Together with the causal body it is the transmigrating soul or jiva, separating from the gross body upon death.
The subtle body is composed of the five subtle elements, the elements before they have undergone panchikarana, and contains:
Other Indian traditions see the subtle body as an eighth-fold aggregate, placing together the mind-aspects and adding avidhya, kamah and karma:
In samkhya, which does not acknowledge a causal body, it is also known as the "linga-sarira". It puts one in the mind of the "atman", it reminds one of the "atman", the controller. It is the beginningless limitation of the "atman", it has no beginning like the "Sthula sarira".
The "dream state" is a distinct state of the subtle body, where the "buddhi" shines itself owing to memory of deeds done in the waking state. It is the indispensable operative cause of all the activities of the individual self.
Sthula sarira - gross body.
"Sthula sarira" or the gross body is the material physical mortal body that eats, breathes and moves (acts). It is composed of many diverse components, produced by one’s "karmas" (actions) in past life out of the elements which have undergone "panchikarana" i.e. combining of the five primordial subtle elements.
It is the instrument of Jiva’s experience, which, attached to the body and dominated by "Ahamkara", uses the body’s external and internal organs of sense and action. The Jiva, identifying itself with the body, in its waking state enjoys gross objects. On its body rests man’s contact with the external world.
The "Sthula sarira"’s main features are "Sambhava" (birth), "Jara" (old age or ageing) and "Maranam" (death), and the "Waking State". The "Sthula sarira" is the anatman.
Correlations with other models.
Three bodies and five sheaths.
The Taittiriya Upanishad describes five koshas, which are also often equated with the three bodies. The three bodies are often equated with the five koshas (sheaths), which cover the Atman:
Four states of consciousness and turiya.
The Mandukya Upanishad describes four states of consciousness, first is called "Vaishvanara" (waking consciousness), second is "Taijasa" (dreaming state), third is "Prajna" (deep sleep state) and fourth is "Turiya" (the superconsciousness state). Waking state, dreaming state, and deep sleep state are equated with the three bodies. while "Turiya" (the superconsciousness state) is a fourth state, which is equated with "Atman" and "Purusha."
Turiya.
Turiya, pure consciousness or superconsciousness, is the fourth state. It is the background that underlies and transcends the three common states of consciousness. 
 In this consciousness both absolute and relative, Saguna Brahman and Nirguna Brahman, are transcended. It is the true state of experience of the infinite ("ananta") and non-different ("advaita/abheda"), free from the dualistic experience which results from the attempts to conceptualise ( "vipalka") reality. It is the state in which ajativada, non-origination, is apprehended.
Four bodies.
Siddharameshwar Maharaj, the guru of Nisargadatta Maharaj, discerns four bodies, by including "Turiya" or the "Great-Causal Body" as a fourth body. Here resides the knowledge of "I am" that cannot be described, the state before Ignorance and Knowledge, or Turiya state
Integral Theory.
The three bodies are a critical component of Ken Wilber's Integral Theory.
Ten bodies of Kundalini Yoga.
Kundalini Yoga as taught by Yogi Bhajan describes ten spiritual bodies: the physical body, three mental bodies and six energy bodies. There is an 11th embodiment of Parallel Unisonness, which represents the divine sound current and is characterized by a pure state of non-dual consciousness.
In Indian philosophy.
Yoga physiology.
The three bodies are an essential part of the Yoga physiology. Yoga aims at controlling the vital energies of the bodies, thereby attaining siddhis (magical powers) and moksha.
Atman vijnana.
According to the Advaita Vedanta tradition, knowledge of the "self" or atman can be gained by self-inquiry, investigating the three bodies, and dis-identifying from them. It is a method which is well-known from Ramana Maharshi, but also from Nisargadatta Maharaj and his teacher Siddharameshwar Maharaj.
By subsequently identifying with the three lower bodies, investigating them, and discarding identification with them when it has become clear that they are not the "I", the sense of "I am" beyond knowledge and Ignorance becomes clearly established.
In this investigation the three bodies are recognized as not being anatman.
In modern culture.
Theosophy.
The later Theosophists speak of seven bodies or levels of existence that include "Sthula sarira" and "Linga sarira".
Yogananda.
The guru Paramahansa Yogananda spoke of three bodies in his 1946 "Autobiography of a Yogi".