The Sources of the Discussion of “Existence and Essence” and the their Metaphysical Distinction in Farabi's Kiitab Alhoroof

Farabi's Kiitab Alhoroof is the first direct philosophical encounter of a Muslim thinker with Greek philosophical thought. Discussions on the analysis of the concepts of "existence-existent" and " Essence " as the main elements of Aristotle's philosophical thought are among the most important parts of this book. Farabi's purpose in writing this book is to lay the groundwork for a fundamental understanding of Greek philosophical thought in the Islamic world. He begins the discussion with the linguistic analysis of "existent" as a non-derivative word (first example) in Arabic and proposes three meanings (“Categories” and “Truthful” and “Individual external thing by essence) for "existent." He combines three meanings into two meanings and focuses on the third meaning (Individual external thing by essence). Al-Farabi tries to offer a way to justify the multiplicity of beings in the universe by proposing categories for the third meaning of "existence" and "essence" as identifiers of external and mental beings, while emphasizing the external union of "existence" and "essence"; Accordance to the author's view, this way is incoherent without assuming the discussion of the "metaphysical distinction of existence from essence"; Farabi's argument on dividing the existence into rich and poor and designing the concept of (Individual mental thing by essence)  in contrast to the concept of "no existence" does not seem understandable except by assuming the metaphysical distinction of existence and essence. His plan paves the way for designing the rules of ontological distinction of "existence" from "essence" are prepared by Ibn Sina.