Aldous Huxley

Those who are offended by the idea that the swallowing of a pill may contribute to a genuinely religious experience should remember that all the standard mortification’s — fasting, voluntary sleeplessness and self-torture — inflicted upon themselves by the ascetics of every religion for the purpose of acquiring merit, are also, like the mind-changing drugs, powerful devices for altering the chemistry of the body in general and the nervous system in particular. Or consider the procedures generally known as spiritual exercises. The breathing techniques taught by the yogi of India result in prolonged suspensions of respiration. These in turn result in an increased concentration of carbon dioxide in the blood; and the psychological consequence of this is a change in the quality of consciousness. Again, meditations involving long, intense concentration upon a single idea or image may also result — for neurological reasons which I do not profess to understand — in a slowing down of respiration and even in prolonged suspensions of breathing.
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