Controversies
Some scientists hold that, because researchers have been unable to demonstrate the existence of Reiki energy with any certainty, it cannot be described as an effective or worthwhile medical practice. Proponents of Reiki claim that they can detect and manipulate this energy, but some scientists claim that if a physical or medical phenomenon has any reliable real-world effects, it should be measurable and able to be observed in rigorously structured studies. Since few scientists feel that Reiki's effects have been demonstrated to any significant degree, most argue that the sensations practitioners of Reiki claim to feel are psychological or the results of practicioners deceiving themselves with magical thinking.
There are also some circles that actively oppose Reiki - generally for the same reasons that any alternative medicine is regularly opposed. For example, many mainstream doctors, academics, and consumer advocates find it disturbing and potentially dangerous that patients with serious diseases like cancer are choosing reiki 'shamans' over trained doctors. While it is understandable for patients to seek non-mainstream remedies when conventional options seem ineffective or untrustworthy, many doctors say that Reiki, like much other alternative medicine, is simply exploiting the fear and hope of people with serious illnesses while offering no real help. Reiki practitioners argue that Reiki is a reliable and effective treatment which is being unfairly dismissed by conservative Western scientific researchers, presenting a few cases of actual disease remission as a proof.
There are various religious groups opposing Reiki. They condemn Reiki as promoting satanic or pagan practices. Once such group is the Unification Church, which cautions its adherents to avoid Reiki on the grounds that Reiki involves channeling the energy of evil spirits. The Roman Catholic Church generally refrains from accusations of Satanism in recent times, but it is common for Catholic thinkers to find Reiki suspicious at best, and some individuals and groups (like Dominicans) actively advise believers against it. Some even go as far as to call Reiki a sect, which is unfair as there is no real structure, guru or chain of command in Reiki community.
See also: Qi, Qigong, Alternative medicine, Alternative healing, Magical thinking