Chi is thought to permeate all things, including the human body. Such metaphysical systems are generally referred to as types of vitalism . One of the key concepts related to chi is the concept of harmony . Trouble, whether in the universe or in the body, is a function of disharmony, of things being out of balance and in need of restoration to equilibrium. When examined under controlled conditions, however, the seemingly paranormal or supernatural feats of masters of chi turn out to be quite ordinary feats of magic, deception, or natural powers.
Vitalism is a popular philosophy in many cultures.
The concept is very popular among New Age thinking, where it generally goes by the name of energy , though the concept bears no resemblance to the concept as used by physicists.