There was a lively and extended debate in Islamic philosophy over the relative status of essence and existence. Avicenna argued that existence is preceded by essence, in that everything that exists only comes into existence because it is brought into existence by something else, except for the ultimate existent, God, the necessary being. Many things might exist, they have essences, but unless something brings them to existence they will remain mere essences without existence. So essence precedes existence. This view was challenged by Averroes, who argued that in an eternal universe anything that could exist would exist, and the existence of a thing is not just an attribute added onto it, but is an essential aspect of its meaning. In any case, if existence is an additional attribute, suggested Shihāb al-Dīn Yaḥyā al-Suhrawardī, then essence would have to exist...