 Together with the translations of the Galenic corpus, Hunayn, Ishaq and other translators associated with them put at the disposal of learned Muslims the Aristotelian corpus in its entirety. This enterprise paved the way to the understanding of Aristotle’s thought as a systematic whole based on the theory of demonstrative science and crowned by the Metaphysics, an understanding which is apparent both in al-Farabi and in  Avicenna.[90]  The translation of Alexander’s treatises On the Principles of the All and On Intellect helped to shape the metaphysical cosmology and noetics of Medieval Arabic philosophy. A hierarchy of separate, intellectual substances is seen as striving towards Aristotle’s Unmoved Mover, also called the “True One” by both al-Farabi and Avicenna, in a purely Neoplatonic and Kindian vein. In doing so, these separate substances imitate the motionless causality of the First Principle by their eternal circular movement (Pines 1986; Martini Bonadeo 2004). This warrants the regularity of the laws of nature in the sublunar world. The Agent Intellect also belongs to this hierarchy of separate substances: the “light” shed by the Agent Intellect is seen as the condition for the intellect that is a faculty of the human soul, namely the potential intellect, to actually know the intelligibles (Walzer 1970).