LAW; ITS DEFINITIONS. 69 



to the mind the operation of some physical 

 cause. We say of an observed Order of facts 

 that it must be due to some "law," meaning 

 simply that all Order involves the idea of some 

 arranging cause, the working of some Force or 

 Forces, (whether they be such as we can further 

 trace and define or not) of which that Order is 

 the index and the result. This is the Second of 

 the five senses specified above. 



And so we pass on by an easy and natural 

 transition to the Third sense in which the word 

 Law is used. This is the most exact and definite 

 of all. The mere general idea that some Force 

 is at the bottom of all phenomena, which are 

 invariably consecutive, is a very different thing 

 from knowing what that Force is in respect to 

 the rule or measure of its operation. Of Law 

 in this sense the one great example, before 

 and above all others, is the Law of Gravitation, 

 for this is a law in the sense not merely 

 of a rule, but of a cause — that is, of a Force ac- 

 curately defined and ascertained according to the 

 measure of its operation, from which Force other 

 phenomena arise by way of necessary conse- 



