122 HOMO V. DARWDT. 



of those -writers who maintain that, of all the diiferences 

 between man and the lower animals, the moral sense or 

 conscience is by far the most important. This sense, as 

 Mackintosh remarks, ' has a rightful supremacy over every 

 other principle of human action ;' it is summed up in that 

 short but imperious word ouglit, so full of high significance. 

 It is the most noble of all the attributes of man, leading 

 him without a moment's hesitation to risk his life for that 

 of a fellow creature ; or, after due deliberation, impelled 

 simply by the deep feeling of right or duty, to sacrifice it 

 in some great cause. Immanuel Kant exclaims, ' Duty ! 

 wondrous thought, that workest neither by fond insinuation, 

 flattery, nor by any threat, but merely by holding up thy 

 naked " law in the soul," and so extorting for thyself always 

 reverence, if not always obedience ; before whom all appe- 

 tites are dumb, however secretly they rebel ; whence thy 

 original ?'" (Vol. i. pp. 70, 71.) 



Lord G. I heartily assent to your quotations from Mack- 

 intosh and Kant, and also to your own remark that the 

 moral sense "is summed up in the short but imperious 

 word ought ; " but do you find anything answering to the 

 moral sense or conscience in the lower animals ? 



Danvin. " The following proposition," my Lord, " seems 

 to me in a high degree probable, namely, that any animal 

 whatever, endowed with well-marked social instincts, would 

 inevitably acquire a moral sense or conscience, as soon as 

 its intellectual powers had become as well developed, or 

 nearly as well developed, as in man." (Vol. i. pp. 71, 72.) 



Lord C. Cannot you give us facts, Mr. Darwin, instead 

 merely of a proposition which seems to you in a high 

 degree probable ? Your hypothesis should be sustained on 

 something more substantial than probabilities — proba- 

 bilities, moreover, which may seem such only to yourself. 



