25^ The Morality of Nature 



vive by their fitness in securing benefits, just as other crea- 

 tures survive by securing physical protection. And in the 

 survival there is the rational development of that mental 

 attitude which made it possible; which is the aptitude 

 for faith. There is also a great influence for the conser- 

 vation of faith as a qualification for survival, in the 

 sexual relations; and equally of those species in which 

 one sex is distinctly differentiated from the other in general 

 strength, and power of defense. Here again an instinct 

 developed by survival, in life much lower than the 

 human, persists into humanity with strength not lessened 

 by the acquirement of intellect, but ennobled therein; 

 and with importance not decreased but intensified. 

 In the great dependence of motherhood and infancy the 

 situation of helplessness, which we formerly saw necessitat- 

 ing sacrifice and perpetuating altruism, must evidently also 

 maintain faith and faithfulness. For these virtues, which 

 hold individuals together in goodwill in ordinary life, 

 are the grand indispensable virtues of that alliance in which 

 the greater life of the lineage acquires periodically its new 

 tenement of flesh. But the confident trust in the bestowal 

 of necessary aid and protection, is only a minor part of the 

 function of faith, as cultivated in the marital union of hu- 

 man beings. The possession of intellect, and the knowledge 

 of good and evil, adds to the instinctive desires of animal 

 nature, an appreciation in humanity, of qualities higher 

 than the purely physical, and indeed sometimes developed 

 at the expense of the physical. The mysterious attraction 

 in which a man and a woman find impulse to that supreme 

 association which shall mingle their natures in their off- 



