Questions about the ultimate reality of things sometimes seem like silly questions to non-philosophers, but to philosophers they are questions of the utmost importance and deepest significance. It is not easy or straightforward to know when some contentious realm of entities is real, or to understand and appreciate what is at issue between those on each side of the dispute. Thus, the questions posed by those who originally framed the realist–anti-realist debate centuries ago – most notably, the nominalists and idealists – have dominated the attention of philosophers ever since. Indeed, questions about the plausibility and character of realism and its alternatives are at the heart of all metaphysical disputes today.

Our aim in this book is to make clear to any intelligent reader what is really at stake in the contemporary realism debate. As far as we know, no other work has really succeeded in doing that. This is unfortunate, because the primary literature is notoriously difficult to grapple with. Consequently, anyone confronting this literature for the first time is likely to be deterred by the abundance of jargon and the almost universal presupposition that the reader has significant background knowledge of the main issues. The uninitiated could be forgiven for giving up quickly after forming the impression that they are somehow uninvited guests at an exclusive club. It is hoped this book might succeed in making the club a little more ecumenical. This book is for those who want to direct their attention squarely towards questions of realism and anti-realism for the first time.