THE HISTORY OF MENTAL DEVELOPMENT 115 



But the word mind calls up before us a long list of 

 powers. And the questions arise, Is one mode and 

 line of mental action just as much the goal of man's 

 development as another ? Is man to cultivate the appe- 

 tite for food and sense gratification just as much as 

 the hunger for righteousness ? Or is appetite in the 

 mind like digestion in the body, a function, necessary 

 indeed and once dominant, but no longer fitted for su- 

 preme control ? Is there in the development of the 

 mental powers or functions just as really a sequence of 

 dominance as in that of the bodily functions ? Are 

 there older and lower powers and modes of action, 

 which, though once supreme, must now be rigidly kept 

 down in their proper lower place ? Are there lower 

 motives, for which the very laws of evolution forbid 

 us to live, just as truly as they forbid a man's living for 

 stomach or brute strength instead of brain and mind ? 

 Are these lower powers merely the foundation on 

 which the higher motives and powers are to rise in 

 their transcendent glory ? This is the question which 

 we now must face, and it is of vital importance. 



We have come to one of the most important and 

 difficult subjects of zoology. Let us distinctly recog- 

 nize that it is not our task to explain the origin of 

 mind, or even of a single mental faculty. I shall take 

 for granted what many of you will not admit, that the 

 germs of all man's highest mental powers are present 

 undeveloped in the mind, if you will call it so, of the 

 amoeba. The limits of this course of lectures have 

 required us to choose between alternatives, either to 

 attempt to prove the truth of the theory of evolution, 

 or taking this for granted, to attempt to find its bear- 

 ings on our moral and religious beliefs. I have 



