Active intellect

Active intellect is a term used in both psychology and philosophy.

Psychology
Active intellect is the psychological concept of knowledge being actively used (as opposed to passive knowledge). For example, if you are speaking French, your knowledge of it is currently active knowledge for you. If you simply know French, but do not happen to be speaking it at the moment, it would be considered passive knowledge. Active intellect is sometimes represented by three wavy lines of equal length stacked together.

Philosophy
The active intellect was the subject of much intense discussion in medieval philosophy. The idea is first encountered in Aristotle's De Anima, in which he discusses the human mind. The early Greek commentators on Aristotle (such as Alexander of Aphrodisias) argued about what it was and how it related to the passive intellect. Later neoplatonist Muslim commentators (Al-Farabi) associated it with the moon, whilst the neo-Aristotelian Muslims (eg Averroes) wrote about how one could conjoin oneself with it thus attaining philosophical nirvana. St. Thomas Aquinas elaborated on Artistotle's distinction between the active intellect and passive intellect.