In political thought, as well as in metaphysics, Avicenna followed the path built by his predecessor, Al-Fa^ra^bi^. For Al-Fa^ra^bi^, the conditions for ideal rule are mostly related with the functions of the soul and the intellect. Avicenna thoroughly studied the soul in its totality and in all its functions, whether rational, animal, or vegetative. He charted the operations of all the senses in detail, including the five external senses and especially the five internal senses located in the brain-namely, common sense, imagery (where the forms of things are stored), imagination, estimation (judging/guessing the imperceptible significance or connotations for us of sensed objects, like friendship and enmity, which also includes instinctive sensing), and memory-and how they could help or prevent or slow down the intellect in finding out the middle term and perceiving intelligibles more generally.