in Buddhist philosophy, one of the five skandhas, or aggregates, that constitute all that exists. Thought ( vijñāna/viññāṇa) is the psychic process that results from other psychological phenomena. The simplest form is knowledge through any of the senses, particularly through the mind (citta), which is regarded as the coordinating organ of the sense impressions. Thoughts are classified by the Theravāda tradition of Buddhism under some 89 headings, depending on their qualities and consequences; other schools classify thoughts in six groups correlated with the five originating senses and the mind. See also skandha.