This must be even truer today and, indeed, I present evidence for it in Chapter 3. The reason so many people don't notice atheists is that many of us are reluctant to 'come out'. My dream is that this book may help people to come out. Exactly as in the case of the gay movement, the more people come out, the easier it will be for others to join them. There may be a critical mass for the initiation of a chain reaction.

American polls suggest that atheists and agnostics far outnumber religious Jews, and even outnumber most other particular religious groups. Unlike Jews, however, who are notoriously one of the most effective political lobbies in the United States, and unlike evangelical Christians, who wield even greater political power, atheists and agnostics are not organized and therefore exert almost zero influence. Indeed, organizing atheists has been compared to herding cats, because they tend to think independently and will not conform to authority. But a good first step would be to build up a critical mass of those willing to 'come out', thereby encouraging others to do so. Even if they can't be herded, cats in sufficient numbers can make a lot of noise and they cannot be ignored.

The word 'delusion' in my title has disquieted some psychiatrists who regard it as a technical term, not to be bandied about. Three of them wrote to me to propose a special technical term for religious delusion: 'relusion'.² Maybe it'll catch on. But for now I am going to stick with 'delusion', and I need to justify my use of it. The Penguin English Dictionary defines a delusion as 'a false belief or impression'. Surprisingly, the illustrative quotation the dictionary gives is from Phillip E. Johnson: 'Darwinism is the story of humanity's liberation from the delusion that its destiny is controlled by a power higher than itself.' Can that be the same Phillip E. Johnson who leads the creationist charge against Darwinism in America today? Indeed it is, and the quotation is, as we might guess, taken out of context. I hope the fact that I have stated as much will be noted, since the same courtesy has not been extended to me in numerous creationist quotations of my works, deliberately and misleadingly taken out of context. Whatever Johnson's own meaning, his sentence as it stands is one that I would be happy to endorse. The dictionary supplied with Microsoft Word defines a delusion as 'a persistent false belief held in the face of strong contradictory evidence, especially as a symptom of psychiatric disorder'. The first part captures religious faith perfectly. As to whether it is a symptom of a psychiatric disorder, I am inclined to follow Robert M. Pirsig, author of Zen and the Art of Motorcycle Maintenance, when he said, 'When one person suffers from a delusion, it is called insanity. When many people suffer from a delusion it is called Religion.'

If this book works as I intend, religious readers who open it will be atheists when they put it down. What presumptuous optimism! Of course, dyed-in-the-wool faith-heads are immune to argument, their resistance built up over years of childhood indoctrination using methods that took centuries to mature (whether by evolution or design). Among the more effective immunological devices is a dire warning to avoid even opening a book like this, which is surely a work of Satan. But I believe there are plenty of open-minded people out there: people whose childhood indoctrination was not too insidious, or for other reasons didn't 'take', or whose native intelligence is strong enough to overcome it. Such free spirits should need only a little encouragement to break free of the vice of religion altogether. At very least, I hope that nobody who reads this book will be able to say, 'I didn't know I could.'

For help in the preparation of this book, I am grateful to many friends and colleagues. I cannot mention them all, but they include my literary agent John Brockman, and my editors, Sally Gaminara (for Transworld) and Eamon Dolan (for Houghton Mifflin), both of whom read the book with sensitivity and intelligent understanding, and gave me a helpful mixture of criticism and advice. Their whole-hearted and enthusiastic belief in the book was very encouraging to me. Gillian Somerscales has been an exemplary copy editor, as constructive with her suggestions as she was meticulous with her corrections. Others who criticized various drafts, and to whom I am very grateful, are Jerry Coyne, J. Anderson Thomson, R. Elisabeth Cornwell, Ursula Goodenough, Latha Menon and especially Karen Owens, critic extraordinaire, whose acquaintance with the stitching and unstitching of every draft of the book has been almost as detailed as my own.

The book owes something (and vice versa) to the two-part television documentary Root of All Evil? which I presented on British television (Channel Four) in January 2006. I am grateful to all who were involved in the production, including Deborah Kidd, Russell Barnes, Tim Cragg, Adam Prescod, Alan Clements and Hamish Mykura. For permission to use quotations from the documentary I thank IWC Media and Channel Four. Root of All Evil? achieved excellent ratings in Britain, and it has also been taken by the Australian Broadcasting Corporation. It remains to be seen whether any US television channel will dare to show it.*)

This book has been developing in my mind for some years. During that time, some of the ideas inevitably found their way into lectures, for example my Tanner Lectures at Harvard, and articles in newspapers and magazines. Readers of my regular column in Free Inquiry, especially, may find certain passages familiar. I am grateful to Tom Flynn, the Editor of that admirable magazine, for the stimulus he gave me when he commissioned me to become a regular columnist. After a temporary hiatus during the finishing of the book, I hope now to resume my column, and will no doubt use it to respond to the aftermath of the book.

For a variety of reasons I am grateful to Dan Dennett, Marc Hauser, Michael Stirrat, Sam Harris, Helen Fisher, Margaret Downey, Ibn Warraq, Hermione Lee, Julia Sweeney, Dan Barker, Josephine Welsh, Ian Baird and especially George Scales. Nowadays, a book such as this is not complete until it becomes the nucleus of a living website, a forum for supplementary materials, reactions, discussions, questions and answers — who knows what the future may bring? I hope that www.richarddawkins.net/, the website of the Richard Dawkins Foundation for Reason and Science, will come to fill that role, and I am extremely grateful to Josh Timonen for the artistry, professionalism and sheer hard work that he is putting into it.

Above all, I thank my wife Lalla Ward, who has coaxed me through all my hesitations and self-doubts, not just with moral support and witty suggestions for improvement, but by reading the entire book aloud to me, at two different stages in its development, so I could apprehend very directly how it might seem to a reader other than myself. I recommend the technique to other authors, but I must warn that for best results the reader must be a professional actor, with voice and ear sensitively tuned to the music of language.

The boy lay prone in the grass, his chin resting on his hands. He suddenly found himself overwhelmed by a heightened awareness of the tangled stems and roots, a forest in microcosm, a transfigured world of ants and beetles and even — though he wouldn't have known the details at the time — of soil bacteria by the billions, silently and invisibly shoring up the economy of the micro-world. Suddenly the micro-forest of the turf seemed to swell and become one with the universe, and with the rapt mind of the boy contemplating it. He interpreted the experience in religious terms and it led him eventually to the priesthood. He was ordained an Anglican priest and became a chaplain at my school, a teacher of whom I was fond. It is thanks to decent liberal clergymen like him that nobody could ever claim that I had religion forced down my throat.*)