Ishin-denshin

Ishin-denshin (以心伝心) is an idiom commonly used in East Asian cultures such as Japan, Korea, China, which denotes a form of interpersonal communication through unspoken mutual understanding. This four-character compound's (or yojijukugo) kanji (Chinese characters) literally translates as "using minds, (are) communicating minds". Sometimes translated into English as "telepathy" or "sympathy", ishin-denshin (i-shim-chon-shim, 이심전심 in Korean) is also commonly rendered as "heart-to-heart communication" or "tacit understanding".

Silent understanding is recognized as a universal human phenomenon; however, some Japanese believe it to be a unique characteristic of Japanese culture. Whereas the Japanese concept of haragei denotes a deliberate form of nonverbal communication, ishin-denshin refers to a passive form of shared understanding. Ishin-denshin is traditionally perceived by the Japanese as sincere, silent communication via the heart or belly (i.e. symbolically from the inside, uchi), as distinct from overt communication via the face and mouth (the outside, soto), which is seen as being more susceptible to insincerities. The introduction of this concept to Japan (via China) is related to the traditions of Zen Buddhism, where the term ishin-denshin refers to direct mind transmission. Zen Buddhism tradition, in turn, draws the concept of ishin-denshin from the first Dharma transmission between Gautama Buddha and Mahākāśyapa in the Flower Sermon.

Ishin-denshin, or non-verbal communication, continues to influence aspects of contemporary Japanese culture and ethics, ranging from business practices to end-of-life care.