12 HOW LITTLE WE KNOW 



pelled to confess that here are factors beyond 

 our comprehension. We say that these living 

 tissues are doing certain things, but we don't 

 know how or why they live, what they are 

 doing or how they do it. We may attempt 

 to explain life as a chemical or a physical 

 process, or as a combination of such processes, 

 but there always comes a point at which we 

 get beyond our depth and we have to fall back 

 on what we call vitality, and we pretend to 

 explain things by using terms which seem to 

 convey more than we really understand. We 

 have learnt a few facts, a few elementary details 

 concerning the marvels of Nature's laboratory, 

 but the more we learn the more must we be 

 impressed by the fact that above all that we 

 can see and beyond all that we can understand 

 there is a great power, a power which pervades, 

 moves, controls, and guides. Sometimes in our 

 intellectual conceit we may claim that we are 

 able to explain all things of which we have 

 had some experience, but if we will only be 

 honest with ourselves we find that our ex- 

 planations are not explanations at all. We 



