8 SCIENTIFIC METHOD 



which is based on the identical principle bodies as 

 interresistant, or mutually impenetrable, must force one 

 another apart. But as science proceeds, simplicity be- 

 comes a snare. Nature is complex. The complexity of 

 nature, which is the limit of mathematical method, requires 

 us to go back to the experience of concrete things. The 

 merit of ancient science was its mathematical form : its 

 weakness was its mathematical exaggeration, feigning sim- 

 plicity and demonstration, when the former was absent and 

 the latter impossible. For example, Aristotle endeavoured 

 to support the old circular astronomy by deductive infer- 

 ences, one of which is as follows. He supposed, without 

 proof, that stars are divine and eternal, and must have 

 eternal motion. He supposed, again without proof, that 

 the only eternal motion is circular, always returning on 

 itself without terminus. From these two hypothetical 

 premisses he deduced that the motion of the stars, being 

 eternal, must be circular. No better example can be 

 found of the abuse of the deductive method when applied 

 too directly to concrete Nature. It is a case of two 

 hypothetical premisses leading to a false conclusion. 

 Every step is false. There is nothing for it but ex- 

 perience. The real question is how the stars move in 

 point of fact ; and when the question began to be rightly 

 put, and the observations of Mars by Tycho Brahe and 

 Kepler contributed the necessary experience, it was soon 

 found to be the fact that the planets at all events do not 

 move in circles or round the earth at all, but in elliptical 

 figures and round the sun. 



The second method is the empirical, which consists 

 mainly of experience and induction. It is the Baconian 

 method. Bacon saw the complexity of Nature and its 

 subtlety far surpassing the subtlety of our sense and 

 intellect He concluded that the method of discovering 



