A recent book about the Islamic law of war and peace suggests comparisons with Christian law which have interesting implications. In this comparative field the plough has so far scratched only the surface. Among the more obvious questions provoked is this: does Christian law derive in this matter from Islamic law, or is the character of holy war always in all religions necessarily similar? Certainly such a book as this reminds us that the similarities between the Christian Crusade and the Islamic holy war—jihād—are more apparent than the differences. It also reminds us that certain general principles must be relevant to the question in any religion. One particular conclusion to which it seems to lead us is that any just war is a holy war. A war is either wrong, or a Crusade; the cause that is proportionate to the evils of war must be a great one indeed and one that claims our whole devotion. I am not, of course, concerned with the question whether there can be a just war at the present day; I only point out some alternatives.

War—struggle, aggression—is a condition of life, whether spiritual or material. Some people have been so unreasonable as to jibe at the combative character of pacifists. It is obvious enough that it is not war, but certain kinds of physical war, that all Christians abhor and some renounce. The holy war against evil angels, the struggle to live righteously, are as really warfare as the war of bombs.