abhiññaa, special kind of seeing and knowing possessed by a spiritually realized being and which enables them to rest confident in their understanding, not reliant upon others.
Abhiññaa is most popularly understood to refer to a series of supernormal powers allegedly possessed by a fully enlightened being. However, only one of these, knowledge of the destruction of the taints (asava), seems to relate specifically to the content of spiritual realisation. This super-knowledge recalls the more archaic significance of the term abhiññaa which is 'higher or special knowledge'.
Seemingly, then, the term refers to an illumined means of cognition, the possession of which constitutes the beginnings of decisive spiritual realisation (Stream Entry). For the Buddha, it is this direct knowing alone that provides the basis for reliable knowledge claims.
However, abhiññaa is not simply an abstract knowing but a profound sensitivity to experience that leads to a corresponding personal transformation. It may be described in terms of an acute, existential responsiveness to the three characteristics of experience (ti-lakkhana) which leads to a complete reorganisation of values, desires, and views.
Even at this exalted stage, the practitioner is nevertheless still vulnerable to misconceptions arising from greed and conceit, tendencies not yet fully eradicated. The culmination of the process of spiritual development is pariññaa, 'exact knowledge' or 'full understanding' (sometimes just aññaa). This level of understanding belongs only to the fully enlightened and is, according to the Buddha, the only completely sure foundation for knowledge.