620 LOGIC OF THE MORAL SCIENCES. 



The actions and feelings of human beings in the social state, are, no 

 doubt, entirely governed by psychological and ethological laws : whatever 

 influence any cause exercises upon the . social phenomena, it exercises 

 through those laws. Supposing therefore the laws of human actions and 

 feelings to be sufficiently known, there is no extraordinary difficulty in de- 

 termining from those laws, the nature of the social effects which any given 

 cause tends to produce. But Avhen the question is that of compounding 

 several tendencies together, and computing the aggregate result of many 

 co-existent causes; and especiall}'' when, by attempting to predict what will 

 actually occur in a given case, we incur the obligation of estimating and 

 compounding the influences of all the causes which happen to exist in that 

 case, we attempt a task to proceed far in which, surpasses the compass of 

 the human faculties. 



If all the resources of science are not sufficient to enable us to calculate, 

 a priori, with complete precision, the mutual action of three bodies gravita- 

 ting toward one another, it may be judged with what prospect of success 

 we should endeavor to calculate the result of the conflicting tendencies 

 which are acting in a thousand different directions and promoting a thou- 

 sand different changes at a given instant in a given society; although we 

 might and ought to be able, from the laws of human nature, to distinguish 

 correctly enough the tendencies themselves, so far as they depend on causes 

 accessible to our observation ; and to determine the direction which each 

 of them, if acting alone, would impress upon society, as well as, in a gener- 

 al way at least, to pronounce that some of these tendencies are more pow- 

 erful than others. 



But, without dissembling the necessary imperfections of the a priori 

 method when applied to such a subject, neither ought we, on the other 

 hand, to exaggerate them. The same objections which apply to the Meth- 

 od of Deduction in this its most difficult employment, apply to it, as we 

 formerly showed,* in its easiest; and would even there have been insuper- 

 able, if there had not existed, as was then fully explained, an appropriate 

 remedy. This remedy consists in the process which, under the name of 

 Verification, we have characterized as the third essential constituent part 

 of the Deductive Method ; that of collating the conclusions of the ratioci- 

 nation either with the concrete phenomena themselves, or, when such are 

 obtainable, with their empirical laws. The ground of confidence in any 

 concrete deductive science is not the a priori reasoning itself, but the ac- 

 cordance between its results and those of observation a j^osteriori. Either 

 of these processes, apart from the other, diminishes in value as the subject 

 increases in complication, and this is in so rapid a ratio as soon to become 

 entirely worthless; but the reliance to be placed in the concurrence of the 

 two sorts of evidence, not only does not diminish in any thing like the 

 same proportion, but is not necessarily much diminished at all. Nothing 

 more results than a disturbance in the order of precedency of the two 

 processes, sometimes amounting to its actual inversion : insomuch that in- 

 stead of deducing our conclusions by reasoning, and verifying them by ob- 

 servation, we in some cases begin by obtaining them provisionally from 

 specific experience, and afterward connect them with the principles of hu- 

 man nature by a priori reasonings, which reasonings are thus a real Verifi- 

 cation. 



The only thinker who, with a competent knowledge of scientific methods 



* Supra, p. 321. 



