Concentration partaking of diminution (Buddhism)

Having attained the first jhana there is still susceptibility to opposition, as perception and understanding are accompanied by desires of the senses.

According to Hinayana Buddhism, concentration is considered as of one kind (monad), of two kinds (dyads), of three kinds (triads), of four kinds (tetrads) or of five kinds (pentad). In the fourth tetrad, where concentration is associated with different conditions of wisdom or understanding, this is the first concentration.