To ask about the origin of the world is to ask why there is something rather than nothing. Although this question may seem like a natural one to us, it would be a mistake to assume that everyone regarded it so. Aristotle did not ask it, and there is serious doubt whether Plato did. Their concern was with the structure of the world, not its origin. Although Plotinus argued that all things have a common source in the first principle, he is thinking about the eternal procession of the world, a process that does not take place in time and is governed by metaphysical necessity. The first suggestion that the existence of the world is contingent and results from the free choice of God occurs in Genesis 1. I say suggestion because the text takes the form of a narrative rather than a philosophic argument and is subject to various interpretations.

In the Middle Ages, the question of origin became central because it was closely linked to questions about God. If the world is not eternal but was brought into existence, it is reasonable to conclude that there was an agent responsible for its coming to be and that this agent can act in a spontaneous fashion. Put otherwise, it is reasonable to conclude that the world is the product of God's will.