OBSERVATION AKd EXPERIMENT. 



Ml 



fc|Uantity of heat to a body merely in- 

 creases its bulk, that a double quantity 

 melts it, and a triple quantity decom- 

 poses it : these three eflFects being 

 heterogeneous, no ratio, whether cor- 

 responding or not to that of the 

 quantities of heat applied, can be 

 established between them. Thus the 

 supposed axiom of the proportionality 

 of effects to their causes fails at the 

 precise point where the principle of 

 the Composition of Causes also fails, 

 viz. where the concurrence of causes 

 is such as to determine a change in 

 the properties of the body generally, 

 and render it subject to new laws, 

 more or less dissimilar to those to 

 which it conformed in its previous 

 state. The recognition, therefore, of 

 any such law of proportionality, is 

 superseded by the more comprehen- 

 sive principle, in which as much of it 

 as is true is implicitly asserted.* 



The general remarks on causation, 

 which seemed necessary as an intro- 

 duction to the theory of the inductive 

 process, may here terminate. That 

 process is essentially an inquiry into 

 cases of causation. All the uniformi- 

 ties which exist in the succession of 

 phenomena, and most of the uni- 

 formities in their co-existence, are 

 either, as we have seen, themselves 

 laws of causation, or consequences 



* Professor Rtin (Logic, ii. 39) points out 

 a class of cases, other tlian that spoken of 

 in the t«xt, which he thinks raust be re- 

 g-.irded as an exception to the Composition 

 of Causes. "Causes that merely make 

 good the collocation for bringing a prime 

 mover into action, or that release a poten- 

 tial force, do not follow any such rule. 

 One man may direct a gun upon a fort as 

 well as three : two sjarks are not more 

 effecttial than one in exploding a barrel of 

 gunpowder. In medicine there is a certain 

 dose that answers the end, and adding to 

 it does no more good." 



I am not sure that these cases are really 

 exceptions. The law of Composition of 

 Causes, I think, is really fulfilled, and the 

 appearance to the contrary is poduced by 

 attending to the remote instead of the im- 

 mediate effect of the causes. In the cases 

 mentioned, the immediate effect of the 

 causes in action is a collocation, and the 

 duplication of th« cause does double the 

 quantity of collocation. Two men could 

 raise the gun to the required angle twice 



resulting from, and corollaries cap- 

 able of being deduced from, such 

 laws. If we could determine what 

 causes are correctly assigned to what 

 effects, and what effects to what 

 causes, we should be virtually ac- 

 quainted with the whole course of 

 nature. All those uniformities which 

 are mere results of causation might 

 then be explained and accounted for ; 

 and every individual fact or event 

 might be predicted, provided we had 

 the requisite data, that is, the requisite 

 knowledge of the circumstances which, 

 in the particular instance, preceded it. 

 To ascertain, therefore, what are 

 the laws of causation which exist in 

 nature ; to determine the effect of 

 every cause, and the causes of all 

 effects, is the main business of In- 

 duction ; and to point out how this 

 is done is the chief object of Inductive 

 Logia 



CHAPTER VII. 



OF OBSERVATION AND EXPERIMENT. 



§ I. It results from the preceding 

 exposition, that the process of as- 

 certaining what consequents in na- 

 ture are invariably connected with 

 what antecedents, or, in other words, 

 what phenomena are related to each 



as quickly as one, though one is enough. 

 Two sparks put two sets of particles of 

 the gunpowder into the state of intes- 

 tine motion which make them explode, 

 though one is suflBcient. It is the colloca- 

 tion itself that does not, by being doubled, 

 always double the effect ; because in many 

 cases a certain collocation, once obtained, 

 is all that is required for the production of 

 the whole amount of effect which can be 

 produced at all at the given time and place. 

 Doubling the collocation with difference of 

 time and place, as by pointing two guns, 

 or explodinjj a second barrel after the first, 

 does double the effect. This remark appliei* 

 still more to Mr. Bun's third example, that 

 of a double dose of medicine ; for a double 

 dose of an aperient does purge more vio- 

 lently, and a double dose of laudanum does 

 produce longer and sounder sleep. But a 

 double purging, or a double amount of 

 narcotism, may have remote effects dif- 

 ferent in kind from the effect of the smaller 

 amo«mt, reducing the case to that of hete- 

 ropathic laws, discussed in the text. 



