"In the beginning God created the heaven and the earth. And the earth was without form, and void and darkness was upon the face of the deep. Genesis 1:1-2 Creation stories try to explain how everything originates from nothing. They leave something out. Nothing also has a history. This book aims to tell it. Books about nothing go back for billions of years. So say astronomers who conjecture that civilizations formed soon after the universe cooled to form stars and planets. What did the antennas of these historians miss that might be captured in this book? The hominid side of nothing. I start with a cousin of homo sapiens who picked up a pebble with holes that seemed to make faces (figure 0.1). Many faces later (each chapter pairs a philosopher with an absence), I conclude with Bertrand Russell's precise analysis of how Caspar does not exist' could be true (chapter 22). About the fifth century BC, three civilizations independently and simultaneously began to philosophize about nothing: China (chapter 3), India (chapters 4 and 5), and Greece (chapters 6-10). They had previously focused on what is the case. Light poured on nature, architecture, and society. But then, in a cross-civilizational black-out, emerged disparate nay-sayers who shifted attention to what is not the case. Behold, the holes in a sponge are absences of sponge! Holes are what make the sponge useful for absorbing liquid. The sponge can exist without the holes. But the holes cannot "exist" without the sponge. They are parasites that depend on their host. Yet the two get along well. Without holes, there would not be so many sponges in your house. Your shadow is a more complex parasite. It is a hole you bore into the light. Your shadow depends on both you and the light. You and light are rather mysterious. Your shadow partakes of both mysteries. Omissions have a yet more complex relationship with action. Actions are events and so are not "things." When you refrain from voting, you do not subtract from what is but rather from what might be. When you regret not voting, your emotion requires counterfactual history: If I had voted, my friend would have won. You are in the land of near-misses. Being is riddled with non-beings. Why are the riddles first posed 2,600 years ago? Why all at once? This negative turn in world philosophy is the coincidence that inspired me to write Nothing: A Philosophical History. My hope was to find some common factor that could explain the simultaneous and independent shift in perspective. The common cause I postulate in this book is the deployment of a cognitive trick dreamed up cave dwellers. Any waking experience of an event can also be explained by the parasitical hypothesis 'he event was merely dreamt.' The parasite takes over the consequences of the host hypothesis The event was perceived"--