122 HUXLEY MEMORIAL LECTURES 



succeeds in disentangling itself sufficiently for 

 the individual to have a certain latitude of choice, 

 a certain feeling, but the necessities of life are 

 there, and make of this power of choice a simple 

 auxiliary of material existence. Thus, along the 

 whole course of the evolution of life, liberty is 

 dogged by automatism, and in the long run is 

 stifled by it. With man alone the chain has been 

 broken. I cannot here enter into detail as to the 

 causes which have permitted life, by a sudden 

 leap from animal to man, to break the chain. I 

 confine myself to saying that the human brain, 

 although, seen from without, it differs little from 

 that of a highly developed animal, yet possesses 

 this remarkable feature that it can oppose to 

 every contracted habit another habit, to every 

 kind of automatism another automatism, so that 

 in man liberty succeeds in freeing itself by 

 setting necessity to fight against necessity. 



I doubt that the evolution of life will ever be 

 explained by a mere combination of mechanical 

 forces. Obviously there is a vital impulse : what 

 I was just calling an impulse towards a higher 

 and higher efficiency, something which ever seeks 

 to transcend itself, to extract from itself more 

 than there is in a word, to create. Now, a force 

 which draws from itself more than it contains, 

 which gives more than it has, is precisely what is 

 called a spiritual force : in fact, I do not see how 

 otherwise spirit is to be defined. But, on the 

 other hand, we are wrong when we fail to take 



