It was in a smoke-filled seminar room in the Philosophy Department of the University of York that I first began thinking about realism. Some of the smoke came from Martin Bell's pipe and I recall gratefully his inspiring, imaginative teaching and personal encouragement. This book has been a long time in gestation; I have incurred many debts in the process and it is a pleasure to be able to record them here. There will be those who think that this book carries with it too much of the whiff of the philosophy seminar room; others will think that there is not enough. Probably the former are right. Certainly, had I written on realism before studying theology, the argument would have been very different. For example, my views on the relationship between science and Christianity have changed significantly and positions for which I would once have argued now seem to me to be mistaken and in danger of distorting the content of Christian faith. For related reasons, I am now more sympathetic towards approaches in theology and the philosophy of religion that are indebted to Wittgenstein. As in the case of the relationship between science and Christianity, it is a better appreciation of the history of philosophy and theology in the modern period that has helped change my mind.

It is no accident, therefore, that I now try to approach the philosophical problems to do with the question of realism and Christianity from a much more theological perspective than once I might have.