EVIDENCE OF UNIVERSAL CAUSATION. 337 



may probably extend further, nothing is more Ukely to suggest experi- 

 ments tending to throw light upon the real properties of the phenom- 

 enon, than the following out such an hypothesis. But to this end it is 

 by no means necessary that the hypothesis be mistaken for a scientific 

 truth. On tlie contrary, that illusion is in this respect, as in every 

 other, an impediment to the progress of real knowledge,- by leading 

 men to restrict themselves arbitrarily to the particular hypothesis 

 which is most accredited at the time, instead of looking out for evez'y 

 class of phenomena between the laws of which and* those of the given 

 phenomenon any analogy exists, and trying all such experiments as 

 may tend to the discovery of ulterior analogies pointing in the same 

 direction. 



CHAPTER XXI. 



OF THE EVIDENCE OF THE LAW OF UNIVERSAL CAUSATION. 



§ 1. We have now completed our review of the logical processes by 

 which the laws, or uniformities, of the sequences of phenomena, and 

 those uniformities in iheir coexistence which depend upon the laws of 

 their sequence, are ascertained. As we recognized in the commence- 

 ment, and have been enabled to see more clearly in the progress of 

 the investigation, the basis of all these logical operations is the uni- 

 versality of the law of causation. The validity of all the Inductive 

 Methods depends upon the assumption that every event, or the begin- 

 ning of every phenomenon, must have some cause ; some antecedent, 

 upon the existence of which it is invariably and unconditionally conse- 

 quent. In the Method of Agreement, this is obvious ; that Method 

 avowedly proceeding on the supposition, that we have found the true 

 cause so soon as we have negatived every other. The assertion is 

 equally true of the Method of Difference. That Method authorizes us 

 to infer a general law from two instances ; one, in which A exists to- 

 gether with a multitude of other circumstances, and B follows; 

 another, in which, A being removed, and all other circumstances 

 remaining the same, B is prevented. What, however, does this prove ? 

 It proves that A, in the particular instance, cannot have had any other 

 cause than B ; but to conclude fi-om this that A was the cause, or that 

 A will on other occasions be followed by B, is only allowable on the 

 assumption that B must have some cause ; that among its antecedents 

 in any single instance in which it occurs, there must bo one which has 

 the capacity of producing it at other times. This being admitted, it is 

 seen that in the case in question that antecedent can be no other than 

 A ; but, that if it be no other than A it must be A-, is not proved, by 

 these instances at least, but taken for granted. Th(;re is no need to 

 spend time in proving that the same thing is true of the other Induc- 

 tive Methods. The universality of tlie law of causation is assumed in 

 them all. 



But is this assumption warranted ? Doubtless (it may be said) 77iost 

 phenomena are connected as effects with some antecedent or cause, 

 that is, are never produced unless sonje assignable fact has preceded 



U U VI \o 



