124 The Descent of Man. Part I. 



the same family. If bad tendencies are transmitted, it is pro* 

 bable that good ones are likewise transmitted. That the state 

 of the body by affecting the brain, has great influence on the 

 moral tendencies is known to most of those who have suffered 

 from chronic derangements of the digestion or liver. The same 

 fact is likewise shewn by the " perversion or destruction of the 

 " moral sense being often one of the earliest symptoms of mental 

 "derangement;"' 17 and insanity is notoriously often inherited. 

 Except through the principle of the transmission of moral ten- 

 dencies, we cannot understand the differences believed to exist in 

 this respect between the various races of mankind. 



Even the partial transmission of virtuous tendencies would 

 be an immense assistance to the primary impulse derived directly 

 and indirectly from the social instincts. Admitting for a moment 

 that virtuous tendencies are inherited, it appears probable, at 

 least in such cases as chastity, temperance, humanity to animals, 

 &c, that they become first impressed on the mental organization 

 through habit, instruction and example, continued during 

 several generations in the same family, and in a quite subordinate 

 degree, or not at all, by the individuals possessing such virtues 

 having succeeded best in the struggle for life. My chief source 

 of doubt with respect to any such inheritance, is that senseless 

 customs, superstitions, and tastes, such as the horror of a Hindoo 

 for unclean food, ought on the same principle to be transmitted. 

 I have not met with any evidence in support of the transmission 

 of superstitious customs or senseless habits, although in itself it 

 is perhaps not less probable than that animals should acquire 

 inherited tastes for certain kinds of food or fear of certain foes. 



Finally the social instincts, which no doubt were acquired by 

 man as by the lower animals for the good of the community, 

 will from the first have given to him some wish to aid his 

 fellows, some feeling of sympathy, and have compelled him to 

 regard their approbation and disapprobation. Such impulses 

 will have served him at a very early period as a rude rule of 

 right and wrong. But as man gradually advanced in intellectual 

 power, and was enabled to trace the more remote consequences 

 of his actions; as he acquired sufficient knowledge to reject 

 baneful customs and superstitions; as he regarded more and 

 more, not only the welfare, but the happiness of his fellow-men ; 

 as from habit, following on beneficial experience, instruction 

 and example, his sympathies became more tender and widely 

 diffused, extending to men of all races, to the imbecile, maimed, 



i- 



Minister, ' Bcdy and Mine/ 1870, p. 60. 



