128 HEREDITY. 



tions are to be ranked among the disingenuous dispu- 

 tants ; nor is it conceivable that any human creature 

 could ever seriously believe that all characters and 

 actions were alike entitled to the affection and re- 

 gard of every one." {Inquiry concerning the Prin- 

 ciples of Morals, Essays, vol. ii. p. 223.) Profit a 

 man may disdain, but duty has a commanding pres- 

 ence, We can refuse to do our duty, but we are 

 unable to deny its authority over us in right. De 

 jure, conscience always rules, although de facto it 

 may not. All languages recognize the distinction 

 between profit and duty, the desirable and the duti- 

 ful, mere expediency and the right. These great 

 phenomena in language must have a natural cause. 

 They are facts. They are hard, unmistakable, endur- 

 ing circumstances in human experience. The ques- 

 tion as to the origin of conscience is not only a vastly 

 more important one than the inquiry concerning the 

 origin of species, but it is one that can be investi- 

 gated by the scientific method almost as readily. I 

 enter on the dancing-plot of Mars he*re for the first 

 time. Many of you may have thought that I have 

 evaded the topic of the origin of conscience. I post- 

 poned it, in order that I might bear the whole brunt 

 of its onset, after discussing the moral sense in de- 

 tail. Having shown what conscience is, I now, with 

 some profit, I hope, may raise the question, How did 

 it originate ? 



It is evident that Darwin's hypothesis of heredi- 

 tary descent, or pangenesis, requires in the gem- 

 mules, innate powers or affinities that amount to 



