xxxi.] LIMITS OF SCIENTIFIC METHOD. 737 



hopes of men. Now I may state that my own studies in 

 logic lead me to call in question such negative inferences. 

 Laws of nature are uniformities observed to exist in the ac- 

 tion of certain material agents, but it is logically impossible 

 to show that all other agents must behave as these do. 

 The too exclusive study of particular branches of physical 

 science seems to generate an over-confident and dogmatic 

 spirit. Rejoicing in the success with which a few groups 

 of facts are brought beneath the apparent sway of laws, the 

 investigator hastily assumes that he is close upon the ulti- 

 mate springs of being. A particle of gelatinous matter is 

 found to obey the ordinary laws of chemistry ; yet it moves 

 and lives. The world is therefore asked to believe that 

 chemistry can resolve the mysteries of existence. 



The, Meaning of Natural Law. 



Pindar speaks of Law as the Ruler of the Mortals and 

 the Immortals, and it seems to be commonly supposed 

 that the so-called Laws of Nature, in like manner, rule 

 man and his Creator. The course of nature is regarded 

 as being determined by invariable principles of mechanics 

 which have acted since the world began, and will act for 

 evermore. Even if the origin of all things is attributed 

 to an intelligent creative mind, that Being is regarded as 

 having yielded up arbitrary power, and as being subject like 

 a human legislator to the laws which he has himself 

 enacted. Such notions I should describe as superficial and 

 erroneous, being derived, as I think, from false views of 

 the nature of scientific inference, and the degree of certainty 

 of the knowledge which we acquire by inductive investi- 

 gation. 



A law of nature, as I regard the meaning of the 

 expression, is not a uniformity which must be obeyed by 

 all objects, but merely a uniformity which is as a matter of 

 fact obeyed by those objects which have come beneath 

 our observation. There is nothing whatever incompa- 

 tible with logic in the discovery of objects which should 

 prove exceptions to any law of nature. Perhaps the best 

 established law is that which asserts an invariable cor- 

 relation to exist between gravity and inertia, so that all 

 gravitating bodies are found to possess inertia, and all 



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