In view of what Frederick II did in his Constitutions, some historians have placed upon his shoulders the full responsibility for the horrors of the stake. This is both unfair and unhistorical. The blame attaches to no single man. The fact of first giving sanction in civil law to death by burning is certainly important, but the importance can easily be exaggerated. Frederick was only giving legal recognition to the actual practice of France and Germany; only introducing what was customary elsewhere into Italy, where tolerance had on the whole been general. Some importance should also be attached to the revival of the study of Roman Law, which showed that Manichæans had suffered death in days before Constantine. In the part played by Frederick II we shall be wise to recognize not something catastrophic but rather a link among very many in a lengthy chain of development.[315] Nor must we forget the significance of the order that burnings are to take place ‘in conspectu populi.’ This is surely an answer to a popular demand that the execution of heretics should be made a public example, a salutary spectacle? The examination of the force of public opinion is almost always more fruitful than that of the motives of individuals, however powerful. What was the attitude of the Church in its crusade against heresy towards the action of Frederick? Being crucial, the question is exceedingly controversial. There have been apologists for the Church who have argued that the whole blame for the burning of heretics rests with the secular power, that Gregory IX had a positive aversion to the idea, that Frederick II’s laws against heretics are to be regarded as an attempt to humiliate the Pope and wrest from the Church jurisdiction which properly belonged to it. This argument makes the establishment of the Inquisition a measure of self-defence, a strategic blow delivered in the great war between the secular and ecclesiastical authorities.[316]