The human being is composed of a number of different forces working along their own lines and attempting to find some kind of harmonious interaction between the parts of the being. There is the physical body, the vital being, the mental being, the psychic being and the spiritual planes beyond that. Many times, the vital or the mental adopts a mode of action without taking into account the needs, and limitations, of the physical body. This is true for spiritual seekers as well as those living the life of the world. In such instances, actions or decisions are taken which force the body and push its past its limits. If proper care is taken, training and development done, and time spent wisely in creating the right circumstances for the physical body, one can see what appear to be extraordinary results. However, in many cases, people believe that holding a mental idea about something means that ‘with faith’ they have actually succeeded in the needed transitions and changes. People can read all about swimming for instance, understand the principles of swimming and ‘how to do it’, but in the end, until they actually get in the water and work to coordinate the body to the action, they don’t actually know how to swim.
Similarly, spiritual seekers frequently extrapolate the achievement of the end result from the aspiration held in front of their vision. This can lead, however, to extraordinary breakdowns when the seeker finds that the body simply is not prepared or readied for what the mind is prepared to exact upon it.
This same issue arises with respect to illness and the ability to marshal the immune system to prevent illness from taking hold. Certainly there is a truth to the power of the mind, and the vital nervous envelope, the aura, to withstand and reject the advent of certain illnesses. Many people have the experience of “feeling a cold coming on” and then strengthening their will and prevent its development. This does not mean, however, that the body itself has been transformed and can withstand any assault no matter how powerful, of forces that can cause it dis-ease.
For those who are willing to devote considerable time and attention to the process of strengthening the nervous sheath and the body, such as through practices of Hatha Yoga or Pranayama, certain signal advances can be documented. Some yogis gain extreme control over the body and its reactions to the point of being able to control not only the voluntary actions, but even the autonomous nervous system and the actions of the organs themselves, slowing the heartbeat, entering into deep states of trance without eating or drinking for days at a time, etc.
The Western celebrity, Harry Houdini, was said to be able to withstand extreme cold, freezing water for extended periods of a time, after habituating his body systematically to endure and accept the cold. Some Tibetan yogis practice the art of tummo, the generation of psychic heat, and they are able to wear freezing wet cloths and dry them with the heat generated without experiencing any form of physical suffering as a result.
For those who have not, however, devoted the time or attention needed to practice these external controls and train the body to accept and endure, the mental formation is generally insufficient, on its own, and they remain subject to ill-health from time to time. There is of course a natural strengthening of the immune system through a positive and focused purpose in life, and it can thus help the seeker avoid numerous inconveniences; yet in the end, until the physical body itself is transformed and fully opens and responds to the higher force, it remains subject to the weakness of the physical plane, and there remain limits to what can be imposed on it without breakdown.
Sri Aurobindo notes: “All illnesses pass through the nervous or vital-physical sheath of the subtle consciousness and subtle body before they enter the physical. If one is conscious of the subtle body or with the subtle consciousness, one can stop an illness on its way and prevent it from entering the physical body. But it may have come without one’s noticing, or when one is asleep or through the subconscient, or in a sudden rush when one is off one’s guard; then there is nothing to do but to fight it out from a hold already gained on the body. Self-defence by these inner means may become so strong that the body becomes practically immune as many yogis are. Still this ‘practically’ does not mean ‘absolutely’. The absolute immunity can only come with the supramental change. For below the supramental it is the result of an action of a Force among many forces and can be disturbed by a disruption of the equilibrium established — in the supramental it is a law of the nature; in a supramentalised body immunity from illness would be automatic, inherent in its new nature.”
“The complete immunity from all illness for which our yoga tries can only come by a total and permanent enlightenment of the below from above resulting in the removal of the psychological roots of ill health — it can’t be done otherwise.”
Sri Aurobindo, Integral Yoga: Sri Aurobindo’s Teaching and Method of Practice, Chapter 10, Difficulties in Transforming the Nature, Illness, pp 318-322