THE PRINCIPLES OF SCIENCE. [CHAP. 



state. When we analyse the meaning which we can 

 attribute to the word cause, it amounts to the existence of 

 suitable portions of matter endowed with suitable quan- 

 tities of energy. If we may accept Home Tooke's asser- 

 tion, cause has etymologically the meaning of thing before. 

 Though, indeed, the origin of the word is very obscure, its 

 derivatives, the Italian cosa, and the French chose, mean 

 simply thing. In the German equivalent ursache, we have 

 plainly the original meaning of thing before, the sache 

 denoting "interesting or important object," the English 

 sake, and ur being the equivalent of the English ere, 

 before. We abandon, then, both etymology and philo- 

 sophy, when we attribute to the laws of causation any 

 meaning beyond that of the conditions under which an 

 event may be expected to happen, according to our 

 observation of the previous course of nature. 



I have no objection to use the words cause and 

 causation, provided they are never allowed to lead us to 

 imagine that our knowledge of nature can attain to cer- 

 tainty. I repeat that if a cause is an invariable and 

 necessary condition of an event, we can never know 

 certainly whether the cause exists or not. To us, then, a 

 cause is not to be distinguished from the group of positive 

 or negative conditions which, with more or less probability, 

 precede an event. In this sense, there is no particular 

 difference between knowledge of causes and our general 

 knowledge of the succession of combinations, in which the 

 phenomena of nature are presented to us, or found to 

 occur in experimental inquiry. 



Distinction of Inductive and Deductive Results. 



We must carefully avoid confusing together inductive 

 investigations which terminate in the establishment of 

 general laws, and those which seem to lead directly to 

 the knowledge of future particular events. That process 

 only can be called induction which gives general Jaws. 

 and it is by the subsequent employment of deduction that 

 we anticipate particular events. If the observation of a 

 number of cases shows that alloys of metals fuse at lower 

 temperatures than their constituent metals, I may with 

 more or less probability draw a general inference to that 



