An Introduction to a Biology 



the ancestors of man bided their time, but believe 

 that it was lack of energy in the line which led to 

 man, which left man with such an unspecialised 

 — that is, with such a backward — ^hand, then we 

 see in the fact that he was able to profit by this 

 mistake the familiar mark of the good craftsman 

 exhibited at an early age. All fashioning, whether of 

 implements or of sentences, consists fundamentally 

 in the intention to carry out a design. But the 

 finished article is only in part the result of the 

 carrying out of the design as intended ; it is also 

 the result, and often to a very large extent, of our 

 ability to profit by mistakes on the way. 



So, whether we incline to the view that man 

 had the ability to profit by the lack of energy on 

 the part of his ancestral line which left the hand 

 undifferentiated, or to the view that the preserva- 

 tion of an undifferentiated type of hand was the 

 result of energy and foresight, the fact remains that 

 it was the possession of this simple type of hand 

 which rendered possible the manufacture and use 

 of tools. But this bald statement does not, I fear, 

 give a very true picture of what happened. 



The mind has an inveterate habit of thinking 

 in terms of cause and effect. It likes to see things 

 in pairs, end on ; and to think of the second as being 

 the effect of the first, which is the cause. This form 

 of thought is probably moulded on everyday human 

 action. The cause is the counterpart of our action ; 

 the effect that of the response produced. Our mind 

 is at ease when it can think in terms of a pusher 

 and a pushed ; of cause and effect. And it is natural 

 that we should apply this way of thinking in our 



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