438 LOGIC OF THE MORAL SCIENCES. 



ideas of resistance, derived from our muscular frame, in which 

 it has been conclusively shown that the idea originates. 

 These therefore are cases of mental chemistry : in which it is 

 proper to say that the simple ideas generate, rather than that 

 they compose, the complex ones. 



With respect to all the other constituents of the mind, its 

 beliefs, its abstruser conceptions, its sentiments, emotions, 

 and volitions ; there are some (among whom are Hartley, and 

 the author of the Analysis) who think that the whole of these 

 are generated from simple ideas of sensation, by a chemistry 

 similar to that which we have just exemplified. These philo- 

 sophers have made out a great part of their case, but I am 

 not satisfied that they have established the whole of it. They 

 have shown that there is such a thing as mental chemistry ; 

 that the heterogeneous nature of a feeling A, considered in 

 relation to B and C, is no conclusive argument against its 

 being generated from B and C. Having proved this, they 

 proceed to show, that where A is found, B and C were or may 

 have been present, and why therefore, they ask, should not A 

 have been generated from B and C ? But even if this evidence 

 were carried to the highest degree of completeness which it 

 admits of; if it were shown (which hitherto it has not, in all 

 cases, been) that certain groups of associated ideas not only 

 might have been, but actually were, present whenever the more 

 recondite mental feeling was experienced ; this would amount 

 only to the Method of Agreement, and could not prove causation 

 until confirmed by the more conclusive evidence of the Method 

 of Difference. If the question be whether Belief is a mere case 

 of close association of ideas, it would be necessary to examine 

 experimentally if it be true that any ideas whatever, provided 

 they are associated with the required degree of closeness, give 

 rise to belief. If the inquiry be into the origin of moral feelings, 

 the feeling for example of moral reprobation, it is necessary to 

 compare all the varieties of actions or states of mind which are 

 ever morally disapproved, and see whether in all these cases 

 it can be shown, or reasonably surmised, that the action or 

 state of mind had become connected by association, in the dis- 

 approving mind, with some particular class of hateful or dis- 



