Agnya chakra or front part of the cerebrum. The intellect controls the mind, the senses, the fructifying samskaras and all activities of the body. In the state of sleep, the intellect relaxes its functions and rests in peace. When the intellect is turned towards enjoyments it causes the bondage of the soul but when it is endowed with vairagya, (dispassion) the soul turns toward liberation. The function of the intellect is to weigh everything in the balance of reason. It discriminates between virtue and vice, truth and untruth, good and bad, right and wrong. The intellect is a powerful tool to guide man on the path of spiritual growth.

Anandamaya Kosha (Bliss Sheath or Causal Body)
The Bliss Sheath is composed of Ahamkara (Ego-principle) and Chitta (Basic mind-stuff). It is luminous like a golden egg. It is very pleasant to see and in meditative vision appears like a mass of dazzling light.

Ahamkara (Ego)
A part of the soul's omnipresent cosmic consciousness that identifies itself with the body, mind and intellect assumes a separate identity of its own. It is not separate it is a part, but it assumes separateness. This separate identity is our individuality our sense of 'I' in every thought, perception and action. This separate sense of 'I' is called Ahamkara or Ego. It is this 'I' that experiences the dualities of happiness and unhappiness, pain and pleasure. The seat of Ego is in the medulla. This Ego creates in us attraction, attachment, possessiveness, anger, jealousy, greed and a host of many other negative emotions. This Ego binds the pristine soul to the impure and imperfect world of matter. Annihilating this Ego, i.e. the feeling of separateness is the path that leads to the release of the soul from its bondage in matter.

Chitta (Feeling or memory )
It is the basic medium, the background, the screen on which, manas and buddhi perform their activities. It is a mass of luminous, white light, transparent, pleasant to behold and extremely sensitive. It is the first principle that begins the process of creation of the body. It is consciousness in motion, in vibration as distinct from pure consciousness of the soul that is vibrationless, motionless. Chitta is the field where the seeds of karma are sown and their harvest reaped. It is the storehouse of all our actions and experiences. It has its seat at the top of the cerebrum.

Antahkarana Chatushthaya (Mind)
This literally means, 'Four-fold inner instrument'. The functions of Manas (Lower emotional mind), Buddhi (Higher discriminative mind), Ahamkara (Ego) and Chitta (feeling or memory) together constitute the four-fold inner instrument. We will represent this in English with Mind in capital M.

The purpose of all yoga is to free this soul from its confinement to the physical, astral and causal bodies and return it to its pristine state of perfection.