4 o6 SCIENCE PROGRESS 



a scientific spirit and by scientific methods, but because he sees 

 that the scientific conquest of this dim region of experience is 

 only just beginning. The science of psychology is not yet 

 sufficiently advanced to gauge with any confidence the limits of 

 insanity, hallucination, error, self-deception, and fraud. Even 

 where the good faith of the experience is not to be questioned, it 

 is impossible to exclude a great variety of interpretations. The 

 evidence is not yet recorded much better than that which we 

 have for the ordinary occurrences of life, though its quality is 

 appreciably rising. Its quantity also has increased, though it is 

 still miserably insufficient for scientific requirements. But the 

 most fatal defect in it is that it has not yet been really subjected 

 to experimental control. It is still mainly observational in its 

 nature, and so the conditions of the phenomena under investiga- 

 tion cannot be explored. 



The result is that it has little or no logical "cogency" as 

 against those whose bias impels them to disbelieve it, even 

 though it has become dangerously attractive to many who 

 merely wish to believe, and not to know. Disputes about 

 " what Psychical Research has proved " must at present end in 

 a drawn battle. For each disputant, by looking at what favours 

 his own interpretation and viewing the evidence in the light of 

 his bias, can justify his belief in his own eyes, though he usually 

 fails to do so in those of his opponent. Neither party can, 

 strictly, " prove " its case, and the great mass of mankind, which 

 only wants to " believe," i.e. not to think, is indifferent, and does 

 little to help either. 



This being so, what, the logician may ask, are the conditions 

 of proof in such a matter ? It is in the answers given to this 

 question that the mischiefs of false logic become most apparent. 

 If we assume that no man has a right to believe in what is not 

 fully proved, and that it is our duty to demand absolutely con- 

 clusive evidence before we lift a hand or stir a foot, and if it is 

 good scientific method to employ every art of pettifogging 

 prosecution and every resource of scientific ingenuity to crush 

 every bit of evidence as it arises, it is clear that no proof will 

 ever be forthcoming. We shall never get to the end we profess 

 to aim at, because we shall never be allowed to take the first 

 step towards it, and whatever facts may exist to be discovered 

 we shall never find them, because we shall not permit ourselves 

 to look for them. But if we lay claim to a right to experiment 



