Abstract

Recent developments in quantum physics postulate the existence of some form of multiverse, often considered inimical to theism. We argue that a cosmology of many worlds is not novel either to philosophy or to theism. The multiverse is not a monolithic concept and we refer to and use the four levels of categorization proposed by Max Tegmark. We trace the idea of a multiverse back to the Milesians and Epicureans in order to initially demonstrate its use of a plenitude argument. We then examine the argument for possible compatibility based on a theistic principle of plenitude in three specifically Christian theists: Origen, Thomas Aquinas, and G. W. Leibniz. We conclude that this argument is sustainable so that if any level of the multiverse actually exists then it is harmonious with theism, and we argue that its fit is most successful if a multiverse is considered as a single possible world. We call this view Thomistic modal realism.