

COMPOSITION OF CAUSES. 407 



from any new combination, until we have tried the specific 

 experiment. 



If this be true of chemical combinations, it is still more 

 true of those far more complex combinations of elements 

 which constitute organized bodies ; and in which those extra- 

 ordinary new uniformities arise, which are called the laws 

 of life. All organized bodies are composed of parts similar to 

 those composing inorganic nature, and which have even them- 

 selves existed in an inorganic state; but the phenomena of 

 life, which result from the juxtaposition of those parts in a 

 certain manner, bear no analogy to any of the effects which 

 would be produced by the action of the component substances 

 considered as mere physical agents. To whatever degree we 

 might imagine our knowledge of the properties of the several 

 ingredients of a living body to be extended and perfected, it 

 is certain that no mere summing up of the separate actions of 

 those elements will ever amount to the action of the living 

 body itself. The tongue, for instance, is, like all other parts 

 of the animal frame, composed of gelatine, fibrin, and other 

 products of the chemistry of digestion, but from no knowledge 

 of the properties of those substances could we ever predict 

 that it could taste, unless gelatine or fibrin could themselves 

 taste ; for no elementary fact can be in the conclusion, which 

 was not in the premises. 



There are thus two different modes of the conjunct action 

 of causes ; from which arise two modes of conflict, or mutual 

 interference, between laws of nature. Suppose, at a given 

 point of time and space, two or more causes, which, if they 

 acted separately, would produce effects contrary, or at least 

 conflicting with each other; one of them tending to undo, 

 wholly or partially, what the other tends to do. Thus, the 

 expansive force of the gases generated by the ignition of gun- 

 powder tends to project a bullet towards the sky, while its 

 gravity tends to make it fall to the ground. A stream running 

 into a reservoir at one end tends to fill it higher and higher, 

 while a drain at the other extremity tends to empty it. Now, 

 in such cases as these, even if the two causes which are in 

 joint action exactly annul one another, still the laws of both 



