1) Concept in epistemology 
Dianoia (Greek: διάνοια) is a term used by Plato for a type of thinking, specifically about mathematical and technical subjects. It is the capacity for, process of, or result of discursive thinking, in contrast with the immediate apprehension that is characteristic of noesis. In Aristotle, knowledge is further divided into the theoretical (...
dianoia The mental faculty used in discursive reasoning.
(Gr. dianoia) The faculty or exercise of thinking, as exhibited especially in the discriminating and conjoining or disjoining of concepts; the discursive understanding (Aristotle). -- G.R.M.
the mental faculty used in discursive reasoning.