The concept of ‘active intellect’ as a stage of the human soul first appeared in the writing of Aristotle. To peripatetic exponents or commentator of Aristotle’s works, philosophers like Ibn Rushd (Averroes), Al – Kindi and St.  Thomas Aquinas, this type of intellect is that of Aristotle. Alexandeer of Aphrodisias referred to it as an absolute non – material existent independent of human beings (Aristotelian unmoved mover).
The most significant peripatetic view of the active intellect as the last divine intelligence in the chain of longitudinal intelligences, something contingent, non – material and independent of human beings can be found in the philosophy of Ibn Sina.
Avecinna’s active intellect is considered to have a wide central function in peripatetic ontology. This type of infellenct as a link between non – materials (longitudinal intelligences) and material existents is taken to be the source of multiplicities in the material world and responsible for administrating the sublunary world.
Its primary function is to give corporeal form to matter (the four elements) and intellecetual form to the rational (non – celestial) souls pertaining to the emanation of universal forms, composties and intelligibles through this intellect to the rational soul along with its passing from pure potency into actuality. The Necessary Being’s Knowledge of changing particulars is fulfilled through the agency of active intellect.
In this way, the active intellect plays a wide sublime functional role and is considered an element of peripatetic philosophy.