ABSTRACT
This chapter explores Fakhr al-Din al-Razi's conception of physics and of the nature of the physical world through a preliminary survey of a number of his early and late works. The science of nature for al-Razi is the science which studies existents that are constituted of matter. Al-Razi defines the three grades of meanings of the term "nature". His definition is similar to the general consensus in Ash'arite kalam which rejects the Avicennan notion of tabfah as an effective causal principle inherent in natural phenomenal processes. He also explores the notion of the existence of a multiverse in the context of his commentary on the Qur'anic verse, All praise belongs to God, Lord of the Worlds. He raises the interesting question of whether the term "worlds" in this verse refers to multiple worlds within this single universe or cosmos, or to many other universes or a multiverse beyond this known universe.
