A Just Cause

Abstract

By the middle of the thirteenth century Christian writers were generally in agreement that the just cause for a war must be defensive and their views prevail today. It is just to defend one’s country, laws and traditional way of life, just to try to recover property unlawfully taken by another, perhaps even just to enforce by physical means a properly delivered judicial sentence. It is not just to wage a war of aggrandisement or of conversion. This principle, we shall see, applied to the crusade no less than to any war, but in the first century of the movement, when the just cause was still a subject of discussion, other justifications for crusading were being put forward. St Augustine’s definition of just violence, that it avenged injuries, presupposed a much less passive attitude on the part of the just than was later to be acceptable, especially in the notion of vengeance, which haunted canon lawyers until c. 1200, after which it seems gradually to have been dropped, and in a wide interpretation of the injuries to be avenged, which could include any violation of righteousness, God’s laws or Christian doctrine. As late as the middle of the thirteenth century Hostiensis seems to have believed that Christendom had an intrinsic right to extend its sovereignty over all those who did not recognise the rule of the Roman Church or Roman Empire.