NATURE AND NURTURE 6 1 



All the machinery in a great industrial exposition may be 

 started by a single electrical contact, but, however much the dis- 

 covery of the button may interest us, it helps us but little ' to 

 understand the result. So it is with living organisms. External 

 conditions press the button, but it takes all the inherent potency 

 of living matter to do the rest. 



It is an error to suppose great knowledge is needful for a 

 clear grasp of first principles. " The largest views are not always 

 the clearest, for he who is short-sighted will be obliged to draw 

 the object nearer, and may, perhaps, by a closer and nearer sur- 

 vey, discover that which had escaped far better eyes." 



The riches of a great store of information "cannot be spared 

 or left behind, but it hindereth the march ; yea, and the care of 

 it sometimes loseth or disturbeth the victory." 



Students who are drifting on the sea of facts, with which the 

 modern laboratory has flooded us, sometimes declare that the 

 doctrine of adaptation is antiquated and unscientific and perni- 

 cious. They tell us that organisms have many properties which 

 are not adaptive, and that we are often unable to tell whether a 

 property is adaptive or not. Of course this is true. No one 

 supposes that susceptibility to poisons, for example, is adaptive as 

 such, and our knowledge of nature is incomplete beyond measure. 



They tell us, too, that' many attempts to explain the uses of 

 parts are fanciful and worthless. Unfortunately this is true also, 

 but the logic which makes it a reason for denying the reality 

 of fitness is enough to raise Paley from his grave. 



While protoplasm is, no doubt, the physical basis of life, the 

 intellectual basis of biology is adjustment. I should like to see 

 hung on the walls of every laboratory Herbert Spencer's defini- 

 tion, to the effect that life is not protoplasm, but adjustment; or 

 the older teaching of the father of zoology, that the essence of 

 a living thing is not what it is made of nor what it does, but why 

 it does it. 



It may seem to some that, since capacity for nurture is part 

 of the nature of living things, the difference between nature and 

 nurture is, after all, apparent rather than real. Since what is 

 transmitted from parent to child is not actual or manifest nature, 

 but only its latent potency, or, in other words, a capacity for 



