A view very commonly encountered in contemporary philosophy of religion is that it is a mistake to expect that faith should be capable of rational defence. The roots of the conception of faith as lacking rational defensibility lie far back in the history of the Church (see for instance St Paul’s remarks on faith as foolishness in I Cor 1), but it is only in the last two centuries that deep pessimism has set in about the prospects of finding really convincing a priori or a posteriori arguments in support of faith. This slide from conviction that faith is rationally warranted has not, of course, been a wholly or even mainly negative phenomenon, for it has stimulated an awareness of commissive and emotional aspects of faith which is proving very valuable in the life of the Church. The importance and profundity of much recent writing about faith is something I have no wish to dispute; yet I want to argue that it is a mistake to represent faith as requiring no support from reason, and I shall urge we are only entitled to that faith we can defend.

My argument is basically a very simple one — so simple indeed that many people will undoubtedly think that it cannot do justice to the complexity of the subject under discussion. The short response to those people is to say that they should not disregard the argument but refute it. To make the argument fully convincing, however, I shall discuss in some detail the theoretical basis which underlies it, and attempt to disarm various strategies for opposing or evading it. Finally, I shall describe a positive approach to the problem of finding reasons for faith.

In its most skeletal form the argument can be stated: faith is, or essentially involves, propositional belief; propositional belief requires reasons; therefore faith requires reasons. This clearly stands in need of some fleshing out.