THE HISTORY OF MENTAL DEVELOPMENT 149 



anticipated. Arid over-indulgence often brought sad 

 results and was followed by a period of penitential 

 fasting. And the appetites for sense gratification 

 must always lead to this result. They not only crave 

 things which " perish with the using ; v temporarily at 

 least, often permanently, the appetite itself perishes 

 with the gratification. 



But what of the appetite, if you will pardon the ex- 

 pression, for truth and right ? All attainment only 

 strengthens it ; and, instead of enslaving, it makes men 

 ever more free. And yet what a power there is in the 

 appetite for truth and righteousness ? In obedience 

 to it man gives his body to be burned, or pours out his 

 life-blood drop by drop for its attainment, and rejoices 

 in the sacrifice. There are victims to appetite : there 

 are only martyrs to truth. This soul hunger for truth 

 and right, growing more intense as the soul is filled 

 with the object of desire, is the only one capable of in- 

 definite development and dominance of the will. This 

 must be and is the mental goal of animal development, 

 if man has a future corresponding in length at all to 

 his past. Otherwise the history of life becomes a 

 " story told by an idiot." For its satisfaction is the 

 only one which never causes satiety, and of which 

 over-indulgence is impossible. All others lead only to 

 a slough of despond, or the deeper and more treach- 

 erous slough of contentment, beyond which rise no 

 delectable mountains or golden city. 



And now in closing let me call your attention to one 

 thought of practical vital importance. 



According to the theory which we have agreed to 

 adopt, higher species have arisen through a process of 

 natural selection, those species surviving which are 



