stigmata and nervous anæsthesia which have been scientifically observed have led to the admission as true of historical narratives of analogous facts, as in the case of the stigmata of certain saints and the possessed nuns of Loudun. But history cannot aid the progress of the direct sciences. It is kept at a distance from reality by its indirect means of information, and must accept the laws that are established by those sciences which come into immediate contact with reality. In order to reject one of these laws new direct observations are necessary. Such revolutions are possible, but they must be brought about from within. History has no power to take the initiative in them.
The solution is not so clear in the case of facts which do not harmonise with a body of historical knowledge or with the sciences, still in the embryonic