LAWS OF MIND. 505 



degree of precision indispensable for collusiveness ; 

 and, considering the difficulty of accurate experimen- 

 tation upon the human mind, it will probably be long 

 before they are so. 



It is further to be remembered,, that even if all 

 which this theory of mental phenomena contends for 

 could be proved, we should not be the more enabled 

 to resolve the laws of the more complex feelings into 

 those of the simpler ones. The generation of one 

 class of mental phenomena from another, whenever it 

 can be made out, is a highly interesting fact in 

 psychological chemistry; but it no more supersedes 

 the necessity of an experimental study of the generated 

 phenomenon, than a knowledge of the properties of 

 oxygen and sulphur enables us to deduce those of 

 sulphuric acid without specific observation and expe- 

 riment. Whatever, therefore, may be the final issue 

 of the attempt to account for the origin of our judg- 

 ments, our desires, or our volitions, from simpler 

 mental phenomena, it is not the less imperative to 

 ascertain the sequences of the complex phenomena 

 themselves, by special study in conformity to the 

 canons of Induction. Thus, in respect of Belief, the 

 psychologist Avill always have to inquire, what beliefs 

 we have intuitively, and according to what laws one 

 belief produces another; what are the laws in virtue 

 of which one thing is recognised by the mind, either 

 rightly or erroneously, as evidence of another thing. 

 In regard to Desire, he will examine what objects we 

 desire naturally, and by what causes we are made to 

 desire things originally indifferent or even disagree- 

 able to us; and so forth. It may be remarked, that 

 the general laws of association prevail among these 

 more intricate states of mind, in the same manner as 

 among the simpler ones. A desire, an emotion, an 



