Could there have been Nothing? This is a fundamental metaphysical question, which has a genuine fascination for many people: most of us wonder why the universe is the way it is, why there is a universe at all? Metaphysical nihilists believe that there could have been no physical universe. Everything that exists could have not existed. It sounds like a plausible enough idea, at first. But what grounds do we have for believing it? Is there a persuasive argument for this view? Or is it merely based on intuition? Maybe there had to be something. Does the nature of possibility itself require the existence of physical (concrete) objects? This book looks at the arguments for and against metaphysical nihilism. It considers the metaphysics of possible worlds; philosophy of mathematics and the nature of concrete objects.