Understanding as knowledge about kinds of knowledge (Buddhism)

Knowledge concerned with meaning, with law, or with the language of meaning or law - whenever this knowledge is the object of knowledge, whenever it is analysed by its spheres and functions, then the understanding which arises is as knowledge about kinds of knowledge.

On the Path of Purification of Hinayana Buddhism, panna (understanding) is considered as of one kind (monad), of two kinds (dyads), of three kinds (triads) or of four kinds (tetrads). There are five dyads, four triads and two tetrads. All have the characteristic of penetrating the individual essences or true nature of states (monad). In the second tetrad, this is one of the four kinds of understanding as concerned with meaning, law, language and perspicuity. The four kinds of understanding are together referred to as the four discriminations or analyses.