The combination of current cosmology, physical theories, ancient cosmogonies, theologies, and metaphysics poses three main questions: Why is there something rather than nothing? Why does being take many forms? What is the origin of everything? Many different answers have been given in various different fields to these questions. In theological, creationist metaphysics, the only answer is the existence of a creator who has given rise not only to everything, but also to the laws that govern existence. Non-theological metaphysics, instead, has engaged in the determination of some first principles (archái), from which derives the reality in its various forms. Science, for a long time, evaded these questions, focusing instead on particular aspects of reality by formulating explanations of natural phenomena. In the course of their current development, physics (including quantum theory) and cosmology have posed questions concerning the origin of the whole universe and the reasons for its existence. They believe it is possible to formulate a theory of everything, just as metaphysical cosmologists and theologians thought. The papers collected in this volume offer interesting contributions to the debates surrounding this ultimate "why" question.