Civilisation : Its Cause and Cure 



well be more distinct from each other than these ; 

 yet if an eclipse had to be calculated for next year 

 it would scarcely matter which theory was used. 

 The truth is that the actual problem is so vast that 

 a prediction of a few years in advance only touches 

 the fringe of it so to speak; yet if the fulfilment of 

 the prediction were taken as a proof of the theory 

 in each of these different cases, it would lead in 

 the end to the most hopelessly contradictory 

 results. 



The success of a prediction therefore only 

 shows that the theory on which it is founded has 

 had practical value so far as a working hypothesis. 

 As working hypotheses, and as long as they are 

 kept down to brief steps which can be verified^ 

 the scientific theories are very valuable indeed 

 we could not do without them ; but when they 

 are treated as objective facts when, for instance, 

 the < law of gravitation " derived as it is from a 

 brief study of the heavenly bodies has a universal 

 truth ascribed to it, and is made to apply to pheno- 

 mena extending over millions of years, and to 

 warrant unverifiable prophecies about the plane- 

 tary orbits, or statements about the age of the earth 

 and the duration of the solar system all one 

 can say is that those who argue so are flying off 

 at a tangent from actual facts. For as the tangent 

 represents the direction of a curve over a small 

 arc, so these theories represent the bearing of 

 facts well enough over a small region of observa- 

 tion ; but as following the tangent we soon lose 

 the curve, so following these theories for any dis- 



