It is especially Prince Caetani and Father Lammens who have disturbed this illusion. According to them, even the data which had been pretty generally regarded as objective, rest chiefly upon tendentious fiction. The generations that worked at the biography of the Prophet were too far removed from his time to have true data or notions; and, moreover, it was not their aim to know the past as it was, but to construct a picture of it as it ought to have been according to their opinion. Upon the bare canvass of verses of the Qorân that need explanation, the traditionists have embroidered with great boldness scenes suitable to the desires or ideals of their particular group; or, to use a favourite metaphor of Lammens, they fill the empty spaces by a process of stereotyping which permits the critical observer to recognize the origin of each picture. In the Sîrah (biography), the distance of the first describers from their object is the same as in the Hadîth (legislative tradition); in both we get images of very distant things, perceived by means of fancy rather than by sight and taking different shapes according to the inclinations of each circle of describers. Now, it may be true that the latest judges have here and there examined the Mohammedan traditions too sceptically and too suspiciously; nevertheless, it remains certain that in the light of their research, the method of examination cannot remain unchanged. We must endeavour to make our explanations of the Qorân independent of tradition, and in respect to portions where this is impossible, we must be suspicious of explanations, however apparently plausible. During the last few years the accessible sources of information have considerably increased, the study of them has become much deeper and more methodical, and the result is that we can tell much less about the teaching and the life of Mohammed than could our predecessors half a century ago. This apparent loss is of course in reality nothing but gain. Those who do not take part in new discoveries, nevertheless, wish to know now and then the results of the observations made with constantly improved instruments. Let me endeavour, very briefly, to satisfy this curiosity. That the report of the bookkeeping might make a somewhat different impression if another accountant had examined it, goes without saying, and sometimes I shall draw particular attention to my personal responsibility in this respect.