552 SCIENTIFIC THOUGHT. 



commerce, of politics and society, in which most of us 

 have to spend the larger portion of the working hours of 

 our existence. We can again put the question, What do 

 we know with certainty of the changes and vicissitudes 

 of this artificial atmosphere which surrounds us ; what 

 of the chances of a fall or rise in prices, of increased 

 or lessened demand, of impending labour troubles, of the 

 risks even of famine, fire, shipwreck, disease, or war ? 

 Again we may say that in general we know the proxi- 

 mate causes, natural or artificial, which may bring them 

 about, but the exact when and where of their occurrence 

 is so slightly known to us that such knowledge is of little, 

 if of any, practical value, and proceeds, moreover, where 

 it exists, more from general good sense and practical 

 experience than from the discoveries of science. Indeed, 

 the latter have, through the wonderful applications in 

 the inventions of arts and crafts, tended to make our 

 artificial atmosphere more complex, liable to more rapid 

 and more drastic changes, and accordingly its features 

 less permanent and less calculable and reliable. 

 3. Thus, in spite of the wonderful increase of scientific 



Uncertainty 



in the con- knowledge and the general diffusion of scientific thought 

 in the course of the century, uncertainty is still the 

 main and dominant characteristic of our life in nature 

 and society ; the atmosphere and climate of each are as 

 fickle and changeable, as incalculable and unreliable, as 

 ever. Neither the great law of gravitation nor the 

 fixed proportions of chemistry, neither the intricate 

 doctrine of undulations nor the conception of energy, 

 neither the knowledge of typical forms of nature nor that 

 of their orderly evolution, has, in the hands of those who 



