Avicenna: On the Three Faculties

The Faculties:  


Divine Spirit/Preserve Species/Preserve Individual
Brain/Liver/Heart
Intellect/Attraction to Pleasure/Avoidance of Pain
Cognition/Affect/Behavior
Nervous Energy/Natural Energy/Vital Energy

Avicenna in his Law of Natural Healing (Canon of Medicine), Lecture 5, describes the three faculties that are referred to in many different ways falls under general physiology. It also contains O. Cameron Gruner’s extensive endnotes.