Amazing Ancient Hindu's Science : Energy & Structure of the Mind . Brilliant model to understand self .

The Five Levels
In the Taittiriya Upanishad, the individual is represented in terms of five different sheaths
or levels that enclose the individual's self. These levels, shown in an ascending order, are:

The physical body (annamaya kosha)

Energy sheath (pranamaya kosha)

Mental sheath (manomaya kosha)

Intellect sheath (vijnanamaya kosha)

Emotion sheath (anandamaya kosha )

These sheaths are defined at increasingly finer levels. At the highest level, above the
emotion sheath, is the self. It is significant that emotion is placed higher than the intellect.

This is a recognition of the fact that eventually meaning is communicated by associations
which are influenced by the emotional state.

The energy that underlies physical and mental processes is called prana. One may look
at an individual in three different levels. At the lowest level is the physical body, at the next
higher level is the energy systems at work, and at the next higher level are the thoughts.

Since the three levels are interrelated, the energy situation may be changed by inputs either
at the physical level or at the mental level. When the energy state is agitated and restless,
it is characterized by rajas; when it is dull and lethargic, it is characterized by tamas; the
state of equilibrium and balance is termed sattva.

The key notion is that each higher level represents characteristics that are emergent
on the ground of the previous level. In this theory mind is an emergent entity, but this
emergence requires the presence of the self.


The Structure of the Mind

The Sankhya system takes the mind as consisting of five components: manas, ahankara,
chitta, buddhi, and atman
Manas is the lower mind which collects sense impressions. Its perceptions shift from
moment to moment. This sensory-motor mind obtains its inputs from the senses of hearing,
touch, sight, taste, and smell. Each of these senses may be taken to be governed by a separate
agent.

Ahankara is the sense of I-ness that associates some perceptions to a subjective and
personal experience.
Once sensory impressions have been related to I-ness by ahankara, their evaluation and
resulting decisions are arrived at by buddhi, the intellect. Manas, ahankara, and buddhi are
collectively called the internal instruments of the mind.
Next we come to chitta, which is the memory bank of the mind. These memories con-stitute the foundation on which the rest of the mind operates. But chitta is not merely
a passive instrument. The organization of the new impressions throws up instinctual or
primitive urges which creates different emotional states.

This mental complex surrounds the innermost aspect of consciousness which is called
atman, the self, brahman, or jiva. Atman is considered to be beyond a finite enumeration of
categories.
All this amounts to a brilliant analysis of the individual. The traditions of yoga and
tantra have been based on such analysis. No wonder, this model has continued to inspire
people around the world to this day.