The Limits of Natural Law. 39 



existence in itself : take away the things, and the 

 mode of their action is taken away. If matter ceased 

 to exist in ponderable form, the law of gravity would 

 cease to have any real existence ; if it remained it 

 would exist, not as a law of things, but as a concep- 

 tion shaped by intelligence. 



If, then, we build on the universality and necessity 

 of any given physical law, if we found our theory on 

 the certainty of its continuance throughout all time, 

 and its dominance over the whole breadth of concrete 

 existence, we put into the law a content to which it 

 has no claim. 



Wherever there are like things in like conditions, 

 we necessarily find the same mode of action ; for like 

 things are things that behave alike : the truth in fact 

 amounts to an identical proposition. But where the 

 law is assumed to be constant, there is always, and 

 must be presupposed, the existence of like things and 

 like conditions. The law does not create the concrete 

 realities that conform to it, nor does it subdue to its 

 sway things lying outside its dominion. It is not a 

 self-existent something exercising an independent 

 authority : it is the mode of behaviour of objects. 

 No law of nature has validity beyond the class of 

 phenomena whose mode of action it expresses. If it 

 be affirmed that any given law has existed at other 

 periods of time, or exists in undiscoverable distances 

 of space, the existence of like phenomena is invariably 

 presupposed. If we ate not entitled to assume the 



