But though there be no _à priori_ impossibility in deviations from the beaten track, yet there is a certain _à priori_ improbability which may seem to justify those who refuse to go into alleged instances of the supernormal. There is a story against Thomas Aquinas, that on being invited by a frisky brother-monk to come and see a cow flying, or some such marvel, he gravely came and saw not, but expressed himself far more astounded at the miracle that a religious man should say "the thing which was not." This is certainly a glorious antithesis to Hume's position. Whether we take it to illustrate the Saint's extreme lack of humour, or a subtler depth of humour veiled under stolidity, or his rigorous veracity, or his guileless confidence in the veracity of others, we certainly cannot approve it as an example of the attitude we ought to observe with regard to every newly recounted marvel. Truly there might be more liberality, more enlightenment, more imagination in such a ready credulity, than in the wall-eyed, ear-stopping scepticism of popular science; but the mere inner possibility of a recounted marvel does not oblige us to search into the matter unless the evidence offered bear some reasonable proportion to the burden it has to support. That this is the case as regards crystal-gazing, telepathy, possession, and kindred manifestation, is what Mr. Lang contends; nor would he have any quarrel with the anthropologists were they not fully impressed with the importance of similar or even weaker cumulative evidence for conclusions which happen to be in harmony with their preconceived hypotheses. Where such evidence exists it must be faced, and at least its existence must be explained.