INTERMIXTURE OF EFFECTS. 2G3 



these conjunct effects, the portion which is dctcrmiucJ by any one of 

 the influencing agents, is generally, as we before remarked, but small; 

 and it must be a more potent cause- than most, if even the tendency 

 whicli it really exerts is nut tluvarted by other tendencies in nearly as 

 many cases as it is fulfilled. 



If so littlb can be done by the experimental nietliod to dotermine the 

 conditions oi' an effect of many combined causes, in the case of medical 

 science, still less is this method applicable to a class of phenomena 

 more complicated than even tliosc of pliy.siology, the phenomena of 

 politics^nd iiistory. There, Plurality of Causes exists ui almost bound- 

 less excess, and the effects are, for the most part, inextricably inter- 

 woven with one another. To adct to the embariassmeut, most of the 

 inquiries in political science relate to the ])ro(luction of effects of a 

 most compreliensive description, such as the jjublic wealth, public 

 security, j'l^iblic morality, and the like: results, liable to be affected 

 directly or indirectly either in jjIus or in mitius by nearly every fact 

 which exists, or event which occurs, in human society. The vulgar 

 notion, that the safe methods on poUtical subjects are those of Baconian 

 induction, that the true guide is not general reasoning but specific 

 experience, will one day be quoted as among the most unecjui vocal 

 marks of a low state of the speculative faculties in any age in which it 

 is accredited. What can be more ludicrous than the sort of parodies 

 on experimental reasoning which one is accustomed to meet with, not 

 in popular discussion only, but in grave treatises when the affairs of 

 nations are the theme. " How," it is asked, " can an institution be 

 bad, when the country has prospered under it '{" " How c&,n such or 

 such causes, have contributed to the prosperity of one country, when 

 another has prospered without them V Whoever makes use of an 

 argument of this kind, not intending to deceive, should be sent back 

 to learn the elements of some one of the n>ore easy physical sciences. 

 Such rensoners ignore the fact of Plurality of Causes in the very case 

 which aff'ords the most signal eiiample of it. So little could be con- 

 cluded, in such a case, from any possible collation of individual instances, 

 that even the impossibility, in social phenomena, of making artificial 

 experiments, a circumstance otherwise so prejudicial to directly induc- 

 tive inquiry, hardly affords, in this case, additional reason of regret. 

 For even if we could try experiments upon a nation, or upon the 

 human race, with as little scruple as M. Majendie tries them upon dogs 

 or rabbits, we should never succeed in making two instances identical 

 in every respect except the presence or absence of some one definite 

 circumstance. The nearest approach to an experiment, in the philo- 

 soj)hical sense, which takes place in politics, is the introduction of a 

 new operative element into national affairs by some special and assign- 

 able measure of government, such as the enactment or repeal of a 

 particular law. But, where there are S(j m^ny influences at wol-k, it 

 requires some time for the influence of any new cause upon national 

 phenomena to become apparent ; and as the causes operating in so 

 extensive a sphere are not only infinitely numerous, but in a state of 

 perpetual alteration, it is always certain that Ix^fore the cjffect of a new 

 cause becomes conspicuous enough to bo a subject of induction, so 

 many of the other influencing circumstance^ will have changed as to 

 vitiate the experiment. 



Two, therefore, of the three possible methods for the study of phe- 



