The Problem of Evil, as we all understand it, is a Christian problem. It does not in fact arise till we accept a sovereign reality, at once absolutely good, or rather loving, and at the same time infinitely powerful, behind the diverse realities of the world. Now this supposition has never really taken root in men's minds outside Christianity. It is when this conception comes up against the unhappy facts of human experience that the problem of evil—at first a scandal—arises; ‘If there is a God all-powerful and all-loving behind this world, how can he make his creatures suffer so?’ But it is important to add that even inside Christianity the problem has taken two profoundly different forms. One was quietly ignored by the first Christian centuries, yet modern minds now seem to know no other and it is this that, we believe, is the problem of evil. That Christian theory of evil which seems to have finally prevailed since the XVIth century regards evil as an abstraction, as opposed to the Manichean doctrine which made of it a thing. But, in distinction to both, the older Christian idea rather denounced in it a person. I should suggest that the phrase ‘problem of evil’ does not in fact suit the older form of thought; it should be rather ‘problem of the Evil One’; and it is quite significant to recall that the ‘Libera nos a malo’ of the Our Father which we translate now as ‘deliver us from evil’ used to be translated always as ‘deliver us from the Evil One’. (In some European languages the struggle between the forms still continues.)