498 THE POPULAR SCIENCE MONTHLY 



Hence, secondly, he was led to define certain methods or canons of 

 induction. It was Bacon who first called attention to the importance 

 of " glaring " or " striking " instances, in which the phenomenon under 

 investigation is thrown into relief ; " parallel " instances, which per- 

 mit of the argument from analogy ; and " crucial " instances, which 

 serve as tests of contrary hypotheses. From Bacon, Mill derived the 

 methods to which he gave such prominence in his Logic, the methods, 

 namely, of " agreement," " difference " and " concomitant variation." 

 By means of these methods it is possible to single out from among the 

 circumstances attending or preceding the phenomenon to be explained, 

 that which is its probable cause. That which is present when the 

 phenomenon is present, which is absent when the phenomenon is 

 absent, and which shows like quantitative changes, may be assumed to 

 be connected with the phenomenon, and to point the way to its ex- 

 planation. 



But, thirdly, it is necessary to supplement observation of the natural 

 course of events with artificial experiments. Nature, like men, will 

 reveal her secrets only when put to the torture. Bacon was a con- 

 sistent advocate of the first-hand manipulation of natural bodies. He 

 saw this to be the only method of study which afforded any prospect of 

 laying bare the more " subtle " physical phenomena, such as heat, light 

 and the transmutation of substances. The later development of physics 

 and chemistry not only confirmed this judgment, but in several signal 

 cases fulfilled definite predictions which Bacon based on it. 



Fourthly, Bacon recommended the comparative and historical 

 method. He was one of the first to appreciate the importance of study- 

 ing all phenomena that develop, in different stages of their development. 

 In the particular case of anatomy, he called attention to the importance 

 of studying the structure of organs in their simpler forms, and using 

 the results as a key to the complex forms. 



V. The Baconian Pragmatism. — Bacon's extraordinary modernism 

 appears not only in his definition of sound and fruitful methods of 

 scientific study, but also in his conception of the relation of science to 

 civilization. And in nothing is he so modern as in this. He asserted 

 that the hope of man lay in his advancing knowledge and control of 

 nature. This idea is undoubtedly a present commonplace, but there 

 are few philosophers that anticipate the commonplaces of mankind 

 by three centuries and a half ! But the idea is too fundamental 

 properly to be called a commonplace. It is the most fruitful idea in 

 modern life, the main presupposition of progress. Bacon sought to 

 promote learning for tlue sake of power. That this is essentially a 

 modern idea will be apparent to any one who will study the motives 

 underlying earlier periods of European civilization. The ancient 

 world had its critical and its dogmatic idea of progress. The 



