In this short book, Roy Jackson has sought to present an outline of the main issues in the philosophy of religion. There must be literally thousands of books on this theme already so to write yet another was perhaps rash; however, Jackson does offer a readable, if inevitably sketchy, outline of the subject. It is aimed at readers with little or no previous knowledge of philosophy or theology but assumes a vaguely Christian background.
The book starts with the Greek philosophers (Plato and Aristotle) and traces how their divergent ideas came to influence Christian theologians such as Aquinas (Islamic theology is touched on only in passing). We then come to the classic "proofs" of God's existence: the cosmological, teleological, and ontological arguments. Jackson makes the important and not always recognized point that the ontological argument as presented by Anselm actually has two forms, the second having emerged as a response to criticism. This second form is more subtle than the version that is often quoted and depends on the claim that God's existence is a necessary consequence of the concept of God. Jackson describes Anselm's second argument as very clever, though I have to say that it strikes me as an example of trying to lift yourself up by your bootstraps. In any case, few subsequent philosophers have accepted that any philosophical proof of God's existence is really valid, and it is certainly unlikely that many non-believers have ever been converted by arguments of this kind. Kierkegaard, indeed, went so far as to say that belief in God was irrational and paradoxical and that this was its only justification, while Pascal famously reduced belief to the level of a wager (it's more rational to believe than not, because if you turn out to be right you will go to heaven while if you're wrong you won't lose much).
Another alleged reason for believing in God is to provide a basis for morality. However, either we must say that God wills things because they are good in themselves, in which case God appears to be unnecessary, or we must say that things are good just because God wills them, which makes morality appear arbitrary. Does this mean that God could make, say, murder a good act? Kant made an important contribution to this debate: he held that morality was independent of belief in God although he himself did believe and thought that belief was a positive motivating force.
Throughout history there have been people who have claimed to have direct experience of God. The influence of Eastern mystical traditions and experiences induced by drugs such as LSD have led to an increasing tendency for many people to base their spiritual beliefs on personal experience rather than on formal religion. Jackson discusses the philosophical questions that claims of this nature raise. Of course, it is impossible to talk about such matters without using words, and this produces its own problems: what, if anything, may talk about God be taken to mean? Jackson therefore includes a chapter on religious language. Discussions of these matters are liable to become exceedingly technical and obscure, but Jackson provides a handy summary of the main positions, including Wittgenstein's idea of "language games".
Almost certainly the single most difficult question for any believer to answer is posed by the existence of evil in the world, which seems to show either that God doesn't exist or that He is unable or unwilling to prevent evil. The attempt to justify God in spite of the existence of evil is called theodicy. In a theological context we can identify two different kinds of evil: natural evil (earthquakes, hurricanes) and moral evil (cruelty, wars, persecution); both pose problems for theists. The existence of natural evil can perhaps be explained by saying that it can't be excluded from a material world (gravity is needed to hold things in place but kills us if we fall off a cliff); moral evil is often said to be the consequence of free will (human beings have the freedom to choose wrongly). However, as Jackson points out, there are serious difficulties with the idea of free will itself. One way out of the dilemma, which has emerged in "process theodicy", is to abandon the notion of an all-powerful God and instead to conceive of God as evolving and suffering together with His creation, but relatively few Christians seem to be very happy with this solution.
Most religions include the concept of an afterlife, and some modern writers, such as John Hick, think that there is no way of coming to terms with suffering unless we believe in this. In his final chapter Jackson outlines the views of various ancient and modern philosophers (Plato, Aristotle, Aquinas, Descartes, Ryle) and touches briefly, and I think unwisely, on evidence that is supposed to bear on the survival issue (near-death experience, ghosts, psychic evidence). Here he seems in danger of straying outside philosophy into science, of which he seems to have a shaky grasp—he even repeats the old canard that we use only a small percentage of our brain. I think that he would have been wiser to use the space to discuss the moral implications of a supposed afterlife and how far it really works as a theodicy. Would an eternity of bliss compensate for the suffering of the innocent in this life?
Jackson's writing is commendably clear and free from jargon and the book would be a good to choice to give to a young person who was undecided about religion and wanted to clarify his or her ideas. Jackson presents the arguments and counter-arguments fairly, in so far as this is possible in such a small compass, and his stance is studiously neutral throughout; it is impossible to deduce from his writing where he himself stands, although I was left with the impression that he thinks it is at least rational to believe in God. It is no doubt the wish to avoid taking sides that accounts for the absence of a final chapter to round things off, but this does mean that the book appears to end somewhat in the air. It would certainly have benefited from an index. Short reading lists are however provided for each chapter.