LAWS OF MIND. 



561 



truth, it leads to an inference not 

 unimportant ; that when nature has 

 endowed an individual with great 

 original susceptibility, he will pro- 

 bably be distinguished by fondness 

 for natural history, a relish for the 

 beautiful and great, and moral en- 

 thusiasm ; where there is but a medio- 

 crity of sensibility, a love of science, 

 of abstract truth, with a deficiency of 

 taste and of fervour, is likely to be 

 the result." 



We see from this example that 

 when the general laws of mind are 

 more accurately known, and, above 

 all, more skilfully applied to the de- 

 tailed explanation of mental peculia- 

 rities, they will account for many 

 more of those peculiarities than is 

 ordinarily supposed. Unfortunately 

 the reaction of the last and present 

 generation against the philosophy of 

 the eighteenth century has produced 

 a very general neglect of this great 

 department of analytical inquiry, of 

 which, consequently, the recent pro- 

 gress has been by no means propor- 

 tional to its early promise. The 

 majority of those who speculate on 

 human nature prefer dogmatically 

 to assume that the mental differences 

 which they perceive, or think they 

 perceive, among human beings are 

 ultimate facts, incapable of being 

 either explained or altered, rather 

 than take the trouble of fitting them- 

 selves, by the requisite processes of 

 thought, for referring those mental 

 differences to the outward causes by 

 which they are for the most part pro- 

 duced, and on the removal of which 

 they would cease to exist. The Ger- 

 man school of metaphysical specula- 

 tion, which has not yet lost its tem- 

 porary predominance in European 

 thought, has had this among many 

 other injurious influences ; and at the 

 opposite extreme of the psychological 

 scale, no writer, either of early or of 

 recent date, is chargeable in a higher 

 degree with this aberration from the 

 true scientific spirit than M. Comte. 



It is certain that, in human beings 

 at least, differences in education and 



in outward circumstances are capable 

 of affording an adequate explanation 

 of by far the greatest portion of char- 

 acter, and that the remainder may 

 be in great part accounted for by 

 physical differences in the sensations 

 produced in different individuals by 

 the same external or internal cause. 

 There are, however, some mental facts 

 which do not seem to admit of these 

 modes of explanation. Such, to take 

 the strongest case, are the various 

 instincts of animals, and the portion 

 of human nature which corresponds 

 to those instincts. No mode has been 

 suggested, even by way of hypothesis, 

 in which these can receive any satis- 

 factory, or even plausible, explanation 

 from psychological causes alone ; and 

 there is great reason to think that 

 they have as positive, and even as 

 direct and immediate, a connection 

 with physical conditions of the brain 

 and nerves as any of our mere sensa- 

 tions have. A supposition which (it 

 is perhaps not superfluous to add) in 

 no way conflicts with the indisputable 

 fact that these instincts may be modi- 

 tied to any extent, or entirely con- 

 quered, in human beings, and to no 

 inconsiderable extent even in some 

 of the domesticated animals, by other 

 mental influences, and by education. 

 Whether organic causes exercise a 

 direct influence over any other classes 

 of mental phenomena is hitherto as 

 far from being ascertained as is the 

 precise nature of the organic condi- 

 tions even in the case of instincts. 

 The physiology, however, of the brain 

 and nervous system is in a state of 

 such rapid advance, and is continually 

 bringing forth such new and interest- 

 ing results, that if there be really a 

 connection between mental peculiari- 

 ties and any varieties cognisable by 

 our senses in the structure of the 

 cerebral and nervous apparatus, the 

 nature of that connection is now in 

 a fair way of being found out. The 

 latest discoveries in cerebral physio- 

 logy appear to have proved that any 

 such connection which may exist is of 

 a radically different character from 



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