When certainty is not possible, or is a matter of nature, a man must be courageous enough to act guided by clues. A clue shrouded in thick darkness must be satisfactory, he must cling to the little he has—otherwise, he locks himself in inertia. So, find the clue! Find it and hold on to it firmly! Follow the path suggested by it and hold on to the possibility—because this is, without a doubt, better than nothing.