Kosha, the Samskrita word signifies a cover, but as per Sandhya Bhasha, or the Twilight Language of Yoga, the word kosha, as utilized in Samkhya Yoga stands for the self.
According to Samkhya Yoga, the Yoga of the Numbering, there are a number of levels down which consciousness travel. As Shakti, or Universal energy and Shiva, or Universal consciousness transform along these levels, they unite and transmute from purer and more rarefied forms of higher consciousness to more substantive forms possessing correspondingly lesser consciousness.
Finally, at the 5th level below that of the pure self, Universal energy and consciousness manifest as bodies with limited mass and consciousness, or living beings, which are led on our planet Earth by the Human species.
At each successive level or ‘fall’ downwards, the pure form of consciousness gets covered by a sheath that corresponds to the reality on the given level. So, for example, on planet Earth, we cannot live and be manifest without a substantive body. So the physical body formed from the Earth elements becomes a covering around the purer consciousness form, in order to be manifest, or be born on this planet in a form that can sense, comprehend and act.
1. Annamaya Kosha
In fact, this, the Earth based covering called the body is the very last of the 5 coverings around the pure consciousness form, and is called the Annamaya Kosha, or the Illusionary Food-Body Self. The entire skeleto-muscular framework of the body, the internal organs and homoeostasis systems, the organs of perception and action, all this, is collectively termed the Annamaya Kosha. And the Annamaya Kosha is formed from our diet and physical lifestyle. Annamaya Kosha is the Body-self.
The asanas of Hatha Yoga affect primarily the Annamaya Kosha, bringing physical homeostasis as a result of their continued practice. The ultimate practices of Hatha Yoga lead to indefinite expansion of homoeostasis, in other words non-ageing. Physical homoeostasis, by bringing the Pranas into balance, affect mental homoeostasis. This is how through an action as simple as performing an asana, in Hatha Yoga, we gain control over the immensely complex mind.
2. Pranamaya Kosha
The fourth covering around the pure consciousness form is the level called Pranamaya Kosha, or the Illusionary Life-force Self. The physical structure or the Annamaya Kosha is a substantive reflection of the insubstantial Pranamaya Kosha. The actions of the Pranas take place through subtle energy channels called Naadis which form the Pranamaya Kosha. Thus the Pranamaya Kosha is the Vital self, the living-energy matrix, the Naadi Sharira, or Energy Channel Body, supporting the physical structure that is the Annamaya Kosha.
This means that we can control, change and evolve the Annamaya Kosha indirectly by affecting the Pranamaya Kosha. The 5 major Pranas, or Life-forces , are termed Prana, or Prime-Force, Apana, or the Down- Dissolver Force, Samana, or the Equaliser Force, Vyana, the Distributor Force and Udana, the Upraised Force. These 5 major Pranas, then have many minor Pranas arising out of their manifold combination.
The interaction of these pranas and their subsidiary pranas, decide our emotional and physical states as well as the state of our minds. Basically, as far as pragmatic Yoga is concerned, both the mental processes and the physical processes can be controlled by control over the Pranamaya Kosha.
The achievement of such a control over the Pranamaya Kosha is the objective of the variegated techniques that comprise the science of Pranayama and Swara Yoga.
3. Manomaya Kosha
The third of the coverings around the pure consciousness form is the Ego covering formed by mental processes, called the Manomaya Kosha, or Illusionary Mind Self.
The 3 parts of the mind, Chitta, or memory, Buddhi, or cognition and Manas, or affectivity, [Link here to the Mind in Yoga article], are the components of their combined complex called Ahamkara, or the ego. This is the ego- self, the persona, the composite of characteristics that make up the character, the waking and dreaming person.
The Manas factor of the mind, led by Iccha, or conative intent, controls the perceptive power of the mind. Based on the type of Iccha that fires the mind, the Buddhi is either turned upwards towards the Vijnanamaya Kosha level of intuition, remains flat at the level of intellectualizing Manomaya Kosha or is turned downwards, towards the instinctive Annamaya Kosha. As we cognize, so we are. Therefore if we cognize on the Annamaya Kosha, we are on the instinctive level, and so on.
The mind, no matter how complex it might seem, is an organ and needs energy or prana to function. What is important for us to know, as concerns the interdependence between mind and prana, is that by controlling the quality and type of prana, and locating such qualified pranas within our energy body, we can generate the required mental state. The practice of this kind of mind state generation through prana amplification is known as Mantra Kriya and its corresponding theory is known as Mantra Vidya.
4. Vijnanamaya Kosha
The second of the coverings around the pure consciousness form is the Vijnanamaya Kosha, or the Illusory Intuitive Self. When the Conative intent in the Manas sector of the mind is turned ‘upwards’ , the mirror-like Manas reflects into the Buddhi, the experience of intuition, which experience is then cognized by the Buddhi as an idea, something original, unique. This is the ‘I as (the intuitive experience of) That’ self. It is the Atma, or the individual Soul, the Sleeper within that awakens unto the bright sun of intuition. This Soul experience, though epiphanous in nature, is not constant-it comes and goes.
And thus, we have in all religious symbolism, the images of saints gazing up, as they reflect within themselves the light of intuition radiating from heavenly firmaments, far above the rock of the intellect, upon which sits the meditating saint.
The ways of being and techniques of practice leading up to the Vijnanamaya Kosha are enshrined in the Tantra-Laya Yogas.
5. Anandamaya Kosha
The first of the coverings that surround the pure consciousness form is the Anandamaya Kosha, or the Illusory Self of Bliss. This is the experience of the Purusha or OverSoul, the ‘All is I’ experience which is an unbroken epiphany. The sure knowledge of its unbroken nature leads to the sensation of continuous and complete Bliss, called Ananda.
At the stage of the Purusha, the consciousness form now stands above the Soul, it experiences the self as the entire matrix of parallel universes.
The Anandamaya Kosha, in terms of the Tattvas, or Elements, is said to be the manifestation of the very first of the 5 formed Elements, Akasha, or Space.
Beyond Space lies the incomprehensible levels of Shiva Loka, or the Worlds of Only-Consciousness, where the entire manifest reality dissolves, leaving only the Subject as Itself. It is only at the level of the Shiva Loka that there is no more Maya or illusion. There are no more coverings. The self shines naked in the splendor of its own Sun.
Therefore, all the 5 selves that we are comprised of, from the instinctive Body self to the divine OverSoul, are illusory in nature, as are their manifold experiences, what we usually term life and living.
But we must remember that each of these 5 selves are real within their own levels, it is just that they are illusionary from a level above. So, for example, the instincts of our body are real, but are seen as illusionary by the intellectual mind. The fixed structure of the intellectual mind is seen as illusory by an intuitive mind, and so on.
Bhuta/ Tattva Shuddhi Kriya, or the Elements Purification Techniques are practiced towards the experience of the Anandamaya Kosha.
We go through all of the above processes of re-cognising our 5 selves, towards the final state evolution of going beyond selves, by the practice of the Shat-Chakra Bhedana, or the Penetration of the Six Vortices-the most advanced of the Kundalini Yoga practices, also known in some traditions as the Anuttara Yoga Tantra. This then marks the nadir, the culmination of the magic Yogic journey of rejoining with our real selves.