COMPOSITION OF CAUSES. 



245 



either of the elements or of the com- 

 pound will vary, if they be carried 

 farther from their centre of attraction, 

 or brought nearer to it ; but whatever 

 affects the one affects the other. They 

 always remain precisely equal. So 

 again, the component parts of a 

 vegetable or animal substance do not 

 lose their mechanical and chemical 

 properties as separate agents, when, 

 by a peculiar mode of juxtaposition, 

 they, as an aggregate whole, acquire 

 physiological or vital properties in 

 addition. Those bodies continue, as 

 before, to obey mechanical and chemi- 

 cal laws, in so far as the operation of 

 those laws is not counteracted by the 

 new laws which govern them as 

 organised beings. When, in short, a 

 concurrence of causes takes place 

 which calls into action new laws 

 bearing no analogy to any that we 

 can trace in the separate operation of 

 the causes, the new laws, while they 

 supersede one portion of the previous 

 laws, may co-exist with another por- 

 tion, and may even compound the effect 

 of those previous laws with their own. 

 Again, laws which were themselves 

 generated in the second mode, may 

 generate others in the first. Though 

 there are laws which, like those of 

 chemistry and physiology, owe their 

 existence to a breach of the principle 

 of Composition of Causes, it does not 

 follow that these peculiar, or, as they 

 might be termed, hcteropathic laws, 

 are not capable of composition with 

 one another. The causes which by 

 one combination have had their laws 

 altered, may carry their new laws 

 with them unaltered into their ulterior 

 combinations. And hence there is no 

 reason to despair of ultimately raising 

 chemistry and physiology to the con- 

 dition of deductive sciences ; for though 

 it is impossible to deduce all chemical 

 and physiological truths from the laws 

 or properties of simple substances or 

 elementary agents, they may possibly 

 be deducible from laws which com- 

 mence when these elementary agents 

 are brought together into some mode- 

 rate number of not very complex com- 



binations. The Laws of Life will 

 never be deducible from the mere 

 laws of the ingredients, but the pro- 

 digiously complex Facts of Life may 

 all be deducible from comparatively 

 simple laws of life ; which laws (de- 

 pending indeed on combinations, but on 

 comparatively simple combinations, of 

 antecedents) may, in more complex cir- 

 cumstances, be strictly compounded 

 with one another, and with the physical 

 and chemical laws of the ingredients. 

 Thedetailsof the vital phenomena, even 

 now, afford innumerable exemplifica- 

 tions of the Composition of Causes ; and 

 in proportion as these phenomena are 

 more accurately studied, there appears 

 more reason to believe that the same 

 laws which operate in the simpler 

 combinations of circumstances, do, in 

 fact, continue to be observed in the 

 more complex. This will be found 

 equally true in the phenomena of 

 mind ; and even in social and political 

 phenomena, the results of the laws of 

 mind. It is in the case of chemical 

 phenomena that the least progress 

 has yet been made in bringing the 

 special laws under general ones from 

 which they may be deduced ; but 

 there are even in chemistry many 

 circumstances to encourage the hope 

 that such general laws will hereafter 

 be discovered. The different actions 

 of a chemical compound will never, 

 undoubtedly, be found to be the sums 

 of the actions of its separate elements ; 

 but there may exist, between the pro- 

 perties of the compound and those of 

 its elements, some constant relation, 

 which, if discoverable by a sufficient 

 induction, would enable us to foresee 

 the sort of compound which will result 

 from a new combination before we 

 have actually tried it, and to judge of 

 what sort of elements some new sub- 

 stance is compounded before we have 

 analysed it. The law of definite pro- 

 portions, first discovered in its full 

 generality by Dalton, is a complete 

 solution of this problem in one, though 

 but a secondary aspect, that of quan- 

 tity: and in respect to quality, we 

 have already aome partial generalisa- 



