CO-EXISTENCES INDEPENDENT OF CAUSATION. 409 



this property, however, has for its cause the presence of a certain quantity 

 of latent heat ; and if that heat could be taken away (as has been done from 

 so many gases in Faraday's experiments), the gaseous form would doubt- 

 less disappear, together with numerous other properties which depend on, 

 or are caused by, that property. 



In regard to all substances which are chemical compounds, and which 

 therefore may be regai'ded as products of the juxtaposition of substances 

 different in Kind from themselves, there is considerable reason to presume 

 that the specific properties of the compound are consequent, as effects, on 

 some of the properties of the elements, though little progress has yet been 

 made in tracing any invariable relation between the latter and the former. 

 Still more strongly will a similar presumption exist, when the object itself, 

 as in the case of organized beings, is no pi'imeval agent, but an effect, which 

 depends on a cause or causes for its veiy existence. The Kinds, therefore, 

 which are called in chemistry simple substances, or elementary natural 

 agents, are the only ones, any of whose properties can with certainty be 

 considered ultimate; and of these the ultimate properties are probably 

 much more numerous than we at present recognize, since every successful 

 instance of the resolution of the properties of their compounds into simpler 

 laws, generally leads to the recognition of properties in the elements dis- 

 tinct from any previously known. The resolution of the laws of the heav- 

 enly motions established the previously unknown ultimate property of a 

 mutual attraction between all bodies ; the resolution, so far as it has yet 

 proceeded, of the laws of crystallization, of chemical composition, electricity, 

 magnetism, etc., points to various polarities, ultimately inherent in the par- 

 ticles of which bodies are composed; the comparative atomic weights of 

 different kinds of bodies were ascertained by resolving into more general 

 laws the uniformities observed in the proportions in which substances com- 

 bine with one another, and so forth. Thus, although every resolution of a 

 complex uniformity into simpler and more elementary laws has an appar- 

 ent tendency to diminish the number of the ultimate projDerties, and really 

 does remove many properties from the list; yet (since the result of this 

 simplifying process is to trace up an ever greater variety of different ef- 

 fects to the same agents) the further we advance in this direction, the 

 greater number of distinct properties we are forced to recognize in one 

 and the same object; the co-existences of which properties must accord- 

 ingly be ranked among the ultimate generalities of nature. 



§ 3. There are, therefore, only two kinds of propositions which assert 

 uniformity of co-existence between properties. Either the properties de- 

 pend on causes or they do not. If they do, the proposition which affirms 

 them to be co-existent is a derivative law of co-existence between effects, 

 and, until resolved into the laws of causation on which it depends, is an 

 empirical law, and to be tried by the principles of induction to which such 

 laws are amenable. If, on the other hand, the properties do not depend 

 on causes, but are ultimate properties, then, if it be true that they invaria- 

 bly CO -exist, they must all be ultimate properties of one and the same 

 Kind ; and it is of these only that the co -existences can be classed as a 

 peculiar sort of laws of nature. 



When we affirm that all crows are black, or that all negroes have woolly 

 hair, we assert a uniformity of co-existence. We assert that the property 

 of blackness or of having woolly hair invariably co-exists with the pi*oper- 

 ties which, in common language, or in the scientific classification that we 



