184 CREATIVE EVOLUTION [chap. 



drowned in the accomplishment of the act, is restored 

 and set free. 1 



The difference must therefore be more radical than a 

 superficial examination would lead us to suppose. It is 

 the difference between a mechanism which engages the 

 attention and a mechanism from which it can be diverted. 

 The primitive steam-engine, as Newcomen conceived it, 

 required the presence of a person exclusively employed to 

 turn on and off the taps, either to let the steam into the 

 cylinder or to throw the cold spray into it in order to con- 

 dense the steam. It is said that a boy employed on this 

 work, and very tired of having to do it, got the idea of 

 tying the handles of the taps, with cords, to the beam of 

 the engine. Then the machine opened and closed the taps 

 itself; it worked all alone. Now, if an observer had com- 

 pared the structure of this second machine with that of 

 the first without taking into account the two boys left to 

 watch over them, he would have found only a slight 

 difference of complexity. That is, indeed, all we can per- 

 ceive when we look only at the machines. But if we cast a 

 glance at the two boys, we shall see that whilst one is 

 wholly taken up by the watching, the other is free to 

 go and play as he chooses, and that, from this point of 

 view, the difference between the two machines is radical, 

 the first holding the attention captive, the second setting 

 it at liberty. A difference of the same kind, we think, 

 would be found between the brain of an animal and the 

 human brain. 



If, now, we should wish to express this in terms of 



» A geologist whom we have already had occasion to cite, N. S. 

 Shaler, well says that ' ' when we come to man, it seems as if we find 

 the ancient subjection of mind to body abolished, and the intellectual 

 parts develop with an extraordinary rapidity, the structure of the 

 body remaining identical in essentials" (Shaier, The Interpretation 

 of Nature, Boston, 1899, p. 187). 



