"e;Multiverse"e; cosmologies imagine our universe as just one of a vast number of others. While this idea has captivated philosophy, religion, and literature for millennia, it is now being considered as a scientific hypothesis -- with different models emerging from cosmology, quantum mechanics, and string theory.Beginning with ancient Atomist and Stoic philosophies, Mary-Jane Rubenstein links contemporary models of the multiverse to their forerunners and explores their current emergence. One reason is the so-called fine-tuning of the universe: nature's constants are so delicately calibrated, it seems they have been set just right to allow life to emerge. For some theologians, these "e;fine-tunings"e; are proof of God; for others, "e;God"e; is an insufficient explanation. One compelling solution: if all possible worlds exist somewhere, then it is no surprise one of them happens to be suitable for life. Yet this hypothesis replaces God with an equally baffling article of faith: the existence of universes beyond, before, or after our own, eternally generated yet forever inaccessible. In sidestepping metaphysics, multiverse scenarios collide with it, producing their own counter-theological narratives.

Rubenstein argues, however, that this interdisciplinary collision provides the condition of its scientific viability, reconfiguring the boundaries among physics, philosophy, and religion.