Buddhist term
The term monkey mind or mind monkey originates from Chinese xīnyuán or Sino-Japanese shin'en (心猿), a word that literally means "heart-mind monkey." It is a Buddhist concept that describes a state of restlessness, capriciousness, and lack of control in one's thoughts. This "mind monkey" metaphor is not only found in Buddhist writings such as Chan or Zen, Consciousness-only, Pure Land, and Shingon, but it has also been adopted in Daoism, Neo-Confucianism, Chinese poetry, theater, and literature. The expression "monkey mind" commonly appears in two reversible four-character idioms paired with yima or iba (意馬), which means "idea horse": Chinese xinyuanyima (心猿意馬) and Japanese ibashin'en (意馬心猿) illustrate the interconnectedness of a restless mind and wandering thoughts. The "Monkey King" Sun Wukong in the classic Chinese novel Journey to the West is an iconic personification of feeling indecisive and unsettled.