CHAPTER VII. 



OF THE UNDERSTANDING, ITS ORIGIN, AND THE ORIGIN OP 



IDEAS. 



This is the most curious and interesting, and at the same time the 

 most difficult subject presented to man in his studies of nature ; it 

 is the subject in which it is most important for him to possess positive 

 knowledge, while yet offering the fewest facihties for its acquisition. 



The question is, how purely physical causes, that is to say, simple 

 relations between different kinds of matter, can produce what we 

 call ideas ; how, out of simple or direct ideas, complex ideas may be 

 formed ; how, in short, out of ideas of any kind, faculties can arise, so 

 astonishing as those of thought, judgment, analysis and reasoning. 



He indeed is more than bold who undertakes such a research, and 

 flatters himself that he has found in nature the origin of these wonder- 

 ful phenomena. 



Assuredly, I have not the presumption to suppose that I have dis- 

 covered their causes ; but I started with the conviction that all acts 

 of intelhgence are natural phenomena and hence derive their source 

 exclusively from physical causes. Seeing that the most perfect animals 

 enjoy the faculty of producing them, I thought that by careful observa- 

 tion, attention, and patience, I might reach, especially through induc- 

 tion, ideas of great moment on this important subject ; I now have to 

 present my conclusions. 



Under the title of understanding or intelligence I include all known 

 intellectual faculties, such as those of forming ideas of various kinds, 

 of comparing, judging, thinking, analysing, reasoning, and, lastly, of 

 recalling ideas previously acquired as well as past thoughts and reason- 

 ings ; this faculty constituting memory. 



All these facidties unquestionably result from acts pecuhar to the 

 organ of intelhgence, and each such act is necessarily the product of 

 relations subsisting between that organ and the nervous fluid moving 

 in it. 



