The support of the Germans was quite indispensable. It was unthinkable to let loose civil war in Germany; the double external danger forced Charles to proceed very cautiously. Inevitably the repeated and sometimes excited negotiations concerning constitutional reform awakened expectations and growing demands, and when the result brought disappointment the irritation was so much the greater. Such events as the German Reformation run their course from intrinsic necessity, and with Martin Luther's especially one gets the impression, as of few other men, that he could not have acted otherwise than he did. The development of German affairs continued to follow the customary paths, and the change to a unified state, which had seemed to be setting in with the accession of Charles, was given up. The religious cleavage, the need for living in harmony with those of another belief, has given the German national spirit a depth and an inward wealth which other peoples do not know.