People generally receive information or are affected by external stimuli through the five senses. However, when one obtains information or is influenced from the outside without using the five senses, it is thought that "Ki"—which cannot be perceived by the five senses—acts as the medium transmitting that information or energy.
Physically, "Ki" is often imagined as a gaseous, flowing substance or as minute particles. Koichi Tohei, founder of the Shin Shin Toitsu Aikido, described "Ki" (written by him as “氣”) as “an infinite gathering of infinitely small elements.” On the other hand, Reiki—a form of healing through touch initiated by Mikao Usui in the late Taisho era—is understood as a form of wave energy. In quantum mechanics, particles and waves are considered two aspects of the same thing, so rather than one being correct over the other, it is likely that both interpretations are valid.
Japanese
What is "Ki"?
In the sense of transmitting information or energy through something imperceptible to the five senses, "Ki" is similar to electromagnetic waves. However, unlike electromagnetic waves, the transmission of information or energy through "Ki" is not experienced in the same way by everyone, lacks reproducibility, and currently cannot be explained by modern science in terms of its mechanisms. These aspects mark a significant difference from electromagnetic wave transmission.
Toshihiro Eguchi, who promoted healing through the hands in the early Showa era under the name “Palm Healing,” once stated: “I cannot say it will cure every disease, but most kinds of illnesses can be healed.” That said, the fact that such methods have not become widely recognized in society as legitimate treatments suggests that their efficacy may be limited. In reality, since modern medical treatment is also not universally effective, it may be better to regard all medical care—whether conventional or alternative—as inherently limited in scope.
Even though the effects of "Ki" cannot yet be fully explained by modern science or medicine, there are numerous reports, albeit limited, of improved health or healing through the use of "Ki". Therefore, exploring "Ki" as one possible method of treatment is, in itself, of considerable value.