The old gentleman asserted that he could judge of the intelligence of his interlocutor by the manner in which the latter received this story. Of course it is impossible to tell every important witness the story of Mungo, but something similar may be made use of which could be sought out of the material in the case. Whoever has anything worthy the name of practice will then be able to judge the manner of the witness’s approach, and especially the degree of intelligence he possesses. The mistake must not be made, however, that this requires splendid deductions; it is best to stick to simple facts. Goethe’s golden word is still true: “The greatest thing is to understand that all fact is theory ... do not look behind phenomena; they are themselves the doctrine.” We start, therefore, with some simple fact which has arisen in the case and try to discover what the witness will do with it. It is not difficult; you may know a thing badly in a hundred ways, but you know it well in only one way. If the witness handles the fact properly, we may trust him. We learn, moreover, from this handling how far the man may be objective. His perception as witness means to him only an experience, and the human mind may not collect experiences without, at the same time, weaving its speculations into them. But though everyone does this, he does it according to his nature and nurture. There is little that is as significant as the manner, the intensity, and the direction in and with which a witness introduces his speculation into the story of his experience. Whole sweeps of human character may show themselves up with one such little explanation. It is for this reason that Kant called the human understanding architectonic; it aims to bring together all its knowledge under one single system, and this according to fixed rules and systems defined by the needs of ordinary mortals. Only the genius has, like nature, his own unknown system. And we do not need to count on this rarest of exceptions. The people who constitute our most complicated problems are the average, and insignificant members of the human race. Hume cited the prophet Alexander quite justly. Alexander was a wise prophet, who selected Paphlagonis as the first scene of his deception because the people there were extraordinarily foolish and swallowed with pleasure the coarsest of swindles. They had heard earlier of the genuineness and power of the prophet, and the smart ones laughed at him, the fools believed and spread his faith, his cause got adherents even among educated people, and finally Marcus Aurelius himself paid the matter so much attention as to rest the success of a military enterprise on a prophecy of Alexander’s. Tacitus narrates how Vespasian cured a blind man by spitting on him, and the story is repeated by Suetonius.