But while Al-Farabi, Ibn Sina (Avicenna), and other Persian and Muslim philosophers hurried, so to speak, over subjects that trenched on religious dogmas, Ibn Rushd delighted in dwelling upon them with full particularity and stress. Thus he says, "Not only is matter eternal, but form is potentially inherent in matter; otherwise, it were a creation "ex nihilo"" (Munk, "Mélanges", p. 444). According to this theory, therefore, the existence of this world is not only a possibility, as Ibn Sina declared—in order to make concessions to the orthodox— but also a necessity.