66 METHOD OF DISCOVERY. 



kind of reasoning. You feel that your worthy friend 

 has you somewhat at a disadvantage. You will feel 

 perfectly convinced in your own mind, however, that 

 you are quite right, and you say to him, " My good 

 friend, I can only be guided by the natural probabilities 

 of the case, and if you will be kind enough to stand 

 aside and permit me to pass, I will go and fetch the 

 police.'' Well, we will suppose that your journey is 

 successful, and that by good luck you meet with a 

 policeman ; that eventually the burglar is found with 

 your property on his person, and the marks correspond 

 to his hand and to his boots. Probably any jury would 

 consider those facts a very good experimental verifica- 

 tion of your hypothesis, touching the cause of the 

 abnormal phenomena observed in your parlour, and 

 would act accordingly. 



Now, in this supposititious case, I have taken 

 phenomena of a very common kind, in order that 

 you might see what are the different steps in an 

 ordinary process of reasoning, if you will only 

 take the trouble to analyze it carefully. All the 

 operations I have described, you will see, are in- 

 volved in the mind of any man of sense in leading 

 him to a conclusion as to the course he should take 

 in order to make good a robbery and punish the 

 offender. I say that you are led, in that case, to 

 your conclusion by exactly the same train of reason- 

 ing as that which a man of science pursues when 

 he is endeavouring to discover the origin and laws 

 of the most occult phenomena. The process is, 

 and always must be, the same ; and precisely the 



