Introduction 1 1 



VII 



Let us then consider, in the first place, some points on which 

 all men are agreed. No one practically doubts that the world in 

 which we live possesses a certain kind and measure of regularity. 

 Every expectation that we entertain, every action that we volun- 

 tarily perform, implies the belief. The most fantastic fairy tale 

 requires it as a background ; there are traces of it even in our dreams. 



Again, we are all at one in treating with suspicion any state- 

 ment which, in our judgement, is inconsistent with the "sort of 

 way things happen " in the world as we conceive it. It seems 

 to us more probable that this or that witness should be mistaken or 

 mendacious, than that the wonders to which he testified should 

 be true. If we have no antecedent ground for thinking him a liar, 

 we probably accept his statements when he confines his narrative 

 to the familiar or the commonplace ; when he deals in marvels 

 we begin to doubt ; when his marvels become too marvellous we 

 frankly disbelieve — though well aware (if we be men of sense) 

 that what is exceedingly marvellous may nevertheless be true. 



Such, roughly speaking, has been, and is, the general procedure 

 of mankind. But evidently it is ill-suited to satisfy historians, 

 philosophers, or men of science. It lacks precision. It rests on 

 no clear principles. It depends too obviously on personal pre- 

 dilections. We seek a criterion of credibility more objective and 

 more fundamental. We should like to know, for example, 

 whether there is any sort of event which is inherently impossible, 

 any sort of statement which,^ without being self-contradictory, 

 may always be pronounced untrue. 



This question will, to many high authorities, seem capable of 

 the simplest answer. Unbroken experience (they will tell us) 

 establishes the uniformity of nature, and it is the uniformity of 

 nature which makes inferences from experience possible. Were 

 this disturbed by miraculous occurrences the very foundations 

 of science would be shaken. On broad general grounds therefore 

 " miracles " must be treated in this scientific age as intrinsically 

 incredible. They never have happened, and they never can 

 happen. Many excellent people have indeed professed to see 

 them, and we need not doubt their veracity. But illusion is easy, 

 credulity is limitless, and there is nothing in- their testimony which 



