Ever since Darwin, numbers of British scientists have tried to bridge the gap between science and religion. Sir Alister Hardy, a marine biologist currently directing studies of religious experience, follows this path with his marshaling of arguments in defense of a natural ""process"" theology--a kind of non-doctrinaire ecumenical faith in divine power, as opposed to any one church's strict dogma or doctrine. The will to believe is a part of man's organic evolution, Hardy says. It has been shaped by ""behavioral"" selection, that is, by drives of exploration or curiosity that in the past led individuals to adopt new forms of behavior. These had survival value and in turn shaped the course of future evolution. Cooperation in hunting carnivores, filial trust, varieties of love are some of these shaping behaviors. Excursions into new and old anthropological theories, Lorenzian and Desmond Morris-type animal behavior hypotheses, and defense of telepathy and other forms of ESP are all adduced to explain the ""biology of God""--i.e., why the relationship between man and God is grounded in biology. The problem with such an approach is that reasonable scientific grounds remain reductive in matters of faith. Any skeptic worth his salt can pick holes in any of Hardy's arguments, and the skeptic's skepticism has as much reason for being as Hardy's theology. The result is a book full of high, sententious piety, which is likely to find its audience among the already convinced.