IO2 Mental action depends upon causation. 



with it in a never-failing or indissoluble manner, so 

 that when the one occurs the other is always present, 

 otherwise it would not be essentially dependent. The 

 only known connections of this kind are those causa- 

 tion and continuity of phenomena, according to which 

 every phenomenon has a cause, and all phenomena 

 are indissolubly connected in endless series. The 

 evidence of the truth of these principles is so vast, 

 that even all mankind thinking through all ages, and 

 after having made an almost infinite number of 

 definite experiments and observations, have never yet 

 met with a single well verified instance of their failure; 

 and we are therefore justified in inferring that they 

 are universal. There are however instances in the 

 physical and chemical sciences, as well as in 

 mental action, where the dependence of phenomena 

 upon those principles is not verr apparent, and has 

 not yet been sufficiently proved, but it is probably in 

 consequence of our imperfect knowledge and limited 

 faculties, that we are unable as yet to fully trace such 

 dependence. The history of science, abundantly 

 proves that we should not assume that a phenomenon 

 arises without a natural cause, simply for the reason 

 that it is very difficult to trace its origin, but wait 

 patiently for more knowledge respecting it. It is 

 unphilosophic and contrary to reason to attribute to 

 occult agencies, effects which may be explicable by 

 ordinary causes, or to refuse to believe in more 

 abstruse causes where the assumption of simple ones 

 is contradicted by some of the evidence. 



