LECTUKE XX. 

 VIS MEDICATRIX NATURAE. 



1. Biological Aspects of the Healing Power of Nature. 2. 

 Psychological Aspects of the Healing Power of Nature. 3. 

 Correspondence in Animate Nature to our Ideals of the True, 

 the Beautiful, and the Good. 4. Humanist Value of the 

 Study of Animate Evolution. 5. Scientific Description of 

 Animate Nature Not Inconsistent with Religious Interpretation. 



1. Biological Aspects of the Healing Power of Nature. 



IN many different ways Man has realised the healing 

 power of Nature vis medicatrix Naturae and all of them 

 are instructive. One might refer, for instance, to the heal- 

 ing virtues in many natural substances, both animal and 

 vegetable, some of which are extraordinarily quaint. It has 

 been re-discovered in modern times that more than one snake 

 carries in its gall-bladder a sure antidote to its own venom. 

 Is not the old advice that the coward should eat of the heart 

 of a lion, so that he might be brave, echoed in the modern 

 treatment of a cretinoid child with the thyroid gland of a 

 sheep? Is it not like a leaf out of an old book of magic 

 to read that an enlightened use of pituitary extract enabled 

 a successful examinee to add in a short time to his height 

 the couple of inches that were required in order to secure 

 a post for which he had proved himself otherwise eligible? 

 It looks as if by taking sufficient thought one might be able 

 to add a cubit to one's stature. 



Interesting too is the reparatory power exhibited by many 

 living creatures. One of the Big Trees or Sequoias which 



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