EMPIRICAL LAWS. 47 



time and place in which they have been found true by 

 observation : and not merely the limits of time and 

 place, but of time, place, and circumstance : for since 

 it is the very meaning of an empirical law that we do 

 not know the ultimate laws of causation upon which 

 it is dependent, we cannot foresee, without actual 

 trial, in what manner or to what extent the introduc- 

 tion of any new circumstance may affect it. 



5. But how are we to know that an uniformity, 

 ascertained by experience, is only an empirical law ? 

 Since, by the supposition, we have not been able to 

 resolve it into higher laws, how do we know that it is 

 not an ultimate law of causation ? 



I answer, that no generalization amounts to more 

 than an empirical law when the only proof upon which 

 it rests is that of the Method of Agreement. For it 

 has been seen that by that method alone we never can 

 arrive at causes. All that the Method of Agreement 

 can do is, to ascertain the whole of the circumstances 

 common to all cases in which a phenomenon is pro- 

 duced: and this of course includes not only the cause 

 of the phenomenon, but all phenomena with which it 

 is connected by any derivative uniformity, whether as 

 being collateral effects of the same cause, or effects of 

 any other cause which, in all the instances we have 

 been able to observe, coexisted with it. The method 

 affords no means of determining which of these uni- 

 formities are laws of causation, and which are merely 

 derivative laws resulting from those laws of causation 

 and from the collocation of the causes. None of 

 them, therefore, can be received in any other character 

 than that of derivative laws, the derivation of which 

 has not been traced ; in other words, empirical laws : 

 in which light, all results obtained by the Method of 



