Part 1 The justification of science: Kuhn's challenge to the rationality of science - the structure of scientific revolutions, Kuhn's retreat, Kuhnian science-rational or irrational? in defence of rational realism - the argument for rational realism, Wittgenstein, Rorty, Davidson and the sense of truth, is realism the best explanation?. Part 2 The rationality of religious belief: does philosophy of religion rest on a mistake? - on justifying religion, the expressive theory and its defence, intellectualism-the theory of primeval stupidity, assessing the argument for the expressive theory, expressive or intellectualist?, the expressive theory and the facts, the case of religion faith and the religious adequacy of explanatory justification - an argument from the motive for faith, the nature of faith, religion and decisive adherence theism and inferring to the best explanation - an objection from the nature of explanation, Darwin and inferring to the best explanation, explanatory power and an objection to ad hocness, the place of simplicity the problem of evil and the philosophy of science - the possibility of evil, the plausibility of evil, anomalies, puzzles and the propriety of mystery.