These two originate with the Sabians—as becomes clear upon reflection. For the Sabians who have departed from affirming the oneness of Allah alone, without partner—like the polytheists and Magians, such as Moses’ Pharaoh, Abraham’s Nimrod, and other human beings—acknowledge absolute existence.
For this reason, the highest of the philosophers’ sciences was metaphysics. By philosophers, I mean the Peripatetics who follow Aristotle, whom they regard as the First Teacher. He wrote on various disciplines, including the branches of logic and natural science, such as animals, place, the heavens and the world, and meteorological phenomena. He also wrote on metaphysics—which they regard as the culmination of their wisdom and the pinnacle of their philosophy. This is the science that later philosophers, such as Ibn Sīnā, call “divine science.”
According to its practitioners, the subject of this science is absolute existence and its concomitants. It thus discusses the existent and the nonexistent, then divides the existent into necessary and contingent, eternal and originated, cause and effect, substance and accident, and the like. It then discusses the various kinds within these divisions and their properties.
Examples include dividing causes into four kinds: the efficient and final causes, which account for a thing’s existence, and matter and form, which account for the essential reality of a composite; and dividing accidents into the nine categorical genera: quality, quantity, position, place, time, relation, possession, acting, and being acted upon—or classifying them into five, according to their differing views.