The ongoing revolution in our understanding of space and time is so central to the drama of our times that no educated person can remain ignorant of it. There is no better illustration of the adventure of ideas, nor the power and practical importance of abstract thought.

Introductory texts should be brief, easy to read and seductive. This text aims to be the clearest philosophical introduction to relativity theory available. It exposes the philosophical heart of issues without jargon, mathematics or logical formulas. Our patron saint is lucidity. It is aimed at those without a background in science, mathematics or philosophy. The hope is to provide thoughtful readers with a sense of where we have come from and where we are going, and thus to offer an invitation to further studies.

This book is a threefold invitation to the philosophy of space and time. It introduces – gently and simply – the new, revolutionary ideas of Einstein. It introduces the concepts and arguments of philosophers, both ancient and modern, which have proved of lasting value. Finally, it introduces the most recent discoveries and the debates raging now, in philosophy and physics, and points out how future developments may unfold.

The text does aim to teach one skill. Careful thinking is at the core of our conception of philosophy. Now that many nations have reorganized themselves as democracies, which depend so much on reasoned debate and persuasion, careful thinking has become a foundation of our social and political lives as well.