COEXISTENCES INDEPENDENT OF CAUSATION. Ill 



that cause : if they are effects of different causes, they cannot 

 coexist unless it be because their causes coexist ; and the uni 

 formity of coexistence, if such there be, between the effects, 

 proves that those particular causes, within the limits of our 

 observation, have uniformly been coexistent. 



2. But these same considerations compel us to recognise 

 that there must be one class of coexistences which cannot 

 depend on causation ; the coexistences between the ultimate 

 properties of things those properties which are the causes 

 of all phenomena, but are not themselves caused by any 

 phenomenon, and a cause for which could only be sought by 

 ascending to the origin of all things. Yet among* these 

 ultimate properties there are not only coexistences, but uni 

 formities of coexistence. General propositions may be, and 

 are, formed, which assert that whenever certain properties are 

 found, certain others are found along with them. We per 

 ceive an object ; say, for instance, water. We recognise it to 

 be water, of course by certain of its properties. Having 

 recognised it, we are able to affirm of it innumerable other 

 properties ; which we could not do unless it were a general 

 truth, a law or uniformity in nature, that the set of properties 

 by which we identify the substance as water, always have those 

 other properties conjoined with them. 



In a former place,* it has been explained in some detail 

 what is meant by the Kinds of objects ; those classes which 

 differ from one another not by a limited and definite, but by 

 an indefinite and unknown, number of distinctions. To this 

 we have now to add, that every proposition by which anything 

 is asserted of a Kind, affirms an uniformity of coexistence. 

 Since we know nothing of Kinds but their properties, the 

 Kind, to us, is the set of properties by which it is identified, 

 and which must of course be sufficient to distinguish it from 

 every other kind.f In affirming anything, therefore, of a Kind, 



* Book i. chap. vii. 



+ In some cases, a Kind is sufficiently identified by some one remarkable 

 property : but most commonly several are required ; each property considered 



