596 LOGIC OF THE MORAL SCIENCES. 



they would cease to exist. The German school of metaphysical specula- 

 tion, Avhich has not yet lost its temporary 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 character ; 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 in- 

 stincts. No mode has been suggested, even by way of hypothesis, in which 

 these can receive any satisfactory, or even plausible, explanation from psy- 

 chological 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 sensations have. A 

 supposition which (it is perhaps not superfluous to add) in no way conflicts 

 with the indisputable fact that these instincts may be modified to any ex- 

 tent, or entirely conquered, in human beings, and to no inconsider^ible ex- 

 tent 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 

 jjrecise nature of the organic conditions 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 interesting 

 results, that if there be really a connection between mental peculiarities and 

 any varieties cognizable by our senses in the structure of the cerebral and 

 nervous apparatus, the nature of that connection is now in a fair way of be- 

 ing found out. The latest discoveries in cerebral physiology appear to have 

 proved that any such connection which may exist is of a radically different 

 character from that contended for by Gall and his followers, and that, what- 

 ever may hereafter be found to be the true theory of the subject, phrenolo- 

 gy at least is untenable. 



CHAPTER V. 



OP ETHOLOGY, OR THE SCIENCE OF THE EOKMATIOX OF CHAEACTEE. 



§ 1. The laws of mind as characterized in the preceding chapter, com- 

 pose the universal or abstract portion of the philosophy of human nature ; 

 and all the truths of common experience, constituting a practical knowledge 

 of mankind, must, to the extent to which they are truths, be results or con- 

 sequences of these. Such familiar maxims, when collected a posteriori 

 from observation of life, occupy among the truths of the science the place 

 of what, in our analysis of Induction, have so often been spoken of under 

 the title of Empirical Laws. 



An Empirical Law (it will be remembered) is a uniformity, whether of 



