XXXI.] MENTAL HABIT. 55 



laws of habit and variation, there is a principle of organ- addition to 

 izing intelligence, which is not a resultant from any unin- j^abit^^^ ° 

 telligent forces, or put together out of any unintelligent 

 elements, but is an ultimate fact of nature. Ju.st so in the 

 science of mind. In the present state of psychology as of The 

 physiology, the most important of all questions is whether g^atf,!*!^ 

 intelligence is an ultimate, primary fact, incapable of being Is intelli- 

 resolved into any other ; or whether it has been put together ultimate 

 out of unintelligent elements. I believe that in mind, as ^^.ct ? 

 in organization, intelligence is an ultimate fact. I believe 

 that in all thought, as in all organization, there is something 

 for Avhich the laws of habit do not account. But it is as 

 yet too soon to discuss this question. I shall keep it for 

 the concluding psychological chapter. 



In the next chapter I shall have to speak of habit and 

 intelligence as acting in the moral nature. 



It will be perceived by any one who is in any degree 

 familiar with psychological studies, that I have in this 

 chapter treated the vast subject of the laws of the associa- 

 tion of ideas very slightly. I have only glanced by 

 allusion at the formation of ideas of groups of sensations, 

 and other yet more complex ideas ; to which class belong 

 all our ideas of external things as distinguished from 

 ideas or memories of simple sensations. And I have dis- 

 missed in a single paragraph the action of mental associa- 

 tion in the processes of reasoning and invention ; though 

 it would take whole chapters, and perhaps a whole volume, 

 to do justice to those subjects. My reason for doing so is. Why I 

 that I do not design, as part of this work, to write a ^^^J^^^a e 

 complete treatise on psychology, any more than a complete association 

 treatise on biology ; — and a complete treatise on the laws ^° "'^ ^" 

 of association, in all their cases and applications, would be 

 nothing less than a complete treatise on psychology. The 

 purpose of the present work is not to enter into full detail 

 on this or any other subject, but to point out what I believe 

 to be the true position of the laws of habit in biology 

 and in psychology, and the relation of the principle of 

 intelligence to that of habit in both. 



