1 92 SCIENCE FROM AN EASY CHAIR 



fact, we can observe its output and experiment on it in 

 a thousand ways, and so get more and more knowledge 

 of it. We are not led to suppose that it is possessed by 

 a demon, nor that in it resides an elsewhere unknown 

 essence. It is enough for us to satisfy ourselves that its 

 qualities, whilst they can be grouped with the chemical 

 and physical qualities of other bodies, so far transcend 

 them in complexity and in immensity of result the 

 whole creation of plant and animal life that their 

 appearance constitutes in effect a new departure, a 

 sudden and, to us, unaccountable acquirement. But 

 then we must remember that it is also an unaccountable 

 thing to us that water suddenly becomes ice at a low 

 temperature, and suddenly becomes vapour at a high 

 temperature, even if we are able to imagine the mechanism 

 which necessitates those changes. We cannot " explain " 

 the nature of things. Even though we can classify 

 them and arrange them in order, and more or less 

 satisfactorily guess what their inner mechanism is, we 

 cannot, in our present state of knowledge, trace them in 

 detail to a first beginning. Even though we believe 

 that such a history lies behind us, we ourselves cannot 

 as yet show how exactly every quality and property 

 and form of matter has developed in due order as a 

 matter of necessity during the cooling of the cosmic gas. 

 All we can do is to ascertain, bit by bit, some sequences, 

 some lines of orderly development and interaction, adding 

 thus step by step to our knowledge of what has taken 

 place. 



