THE DEDUCTIVE METHOD. 



299 



Two, therefore, of the three possible 

 methods for the study of phenomena 

 resulting from the composition of 

 many causes, being, from the very 

 nature of the case, inefficient and illu- 

 sory, there remains only the third, — 

 that which considers the causes sepa- 

 rately, and infers the effect from the 

 balance of the different tendencies 

 which produce it : in short, the de- 

 ductive or tt priwn method. The 

 more particular consideration of this 

 intellectual process requires a chapter 

 to itself. 



CHAPTER XI. 



OK THE DEDUCTIVE METHOD. 



§ I. The mode of investigation 

 which, from the proved inapplicabi- 

 lity of direct methods of observation 

 and experiment, remains to us as the 

 main source of the knowledge we 

 possess or can acquire respecting the 

 conditions and laws of recurrence 

 of the more complex phenomena, is 

 called, in its most general expression, 

 the Deductive Method, and consists 

 of three operations — the first, one of 

 direct induction ; the second, of ra- 

 tiocination ; the third, of verification. 



I call the first step in the process 

 an inductive operation, because there 

 must be a direct induction as the 

 basis of the whole, though in many 

 particular investigations the place of 

 the induction may be supplied by a 

 prior deduction ; but the premises of 

 this prior deduction must have been 

 derived from induction. 



The problem of the Deductive Me- 

 thod is to find the law of an effect 

 from the laws of the dififerent ten- 

 market." But this experiment would be 

 quite inconclusive merely as an experi- 

 ment. It can only serve, as any experi- 

 ment may, to verify the conclusion of a 

 deduction. Unless we already knew by 

 our knowledge of the motives which act on 

 business men that the prospect of war 

 tends to derange the money-market, we 

 should never have been able to prove a 

 connection between the two facts, unless 

 after having ascertained historically that 

 the one followed the other in too great a 



dencies of which it is the joint result. 

 The first requisite, therefore, is to 

 know the laws of those tendencies — 

 the law of each of the concurrent 

 causes ; and this supposes a previous 

 process of observation or experiment 

 upon each cause separately, or else a 

 previous deduction, which also must 

 depend for its ultimate premises on 

 observation or experiment. Thus, if 

 the subject be social or historical 

 phenomena, the premises of the De- 

 ductive Method must be the laws of 

 the causes which determine that class 

 of phenomena ; and those causes are 

 human actions, together with the 

 general outward circumstances under 

 the influence of which mankind are 

 placed, and which constitute man's 

 position on the earth. The Deductive 

 Method applied to social phenomena 

 must begin, therefore, by investigate 

 ing, or must suppose to have been 

 already investigated, the laws of 

 human action, and those propertie.s 

 of outward things by which the ac- 

 tions of human beings in society are 

 determined. Some of these general 

 truths will naturally be obtained by 

 observation and experiment, others 

 by deduction ; the more complex laws 

 of human action, for example, may 

 be deduced from the simpler ones, 

 but the simple or elementary laws 

 will always and necessarily have been 

 obtained by a directly inductive pro- 

 cess. 



To ascertain, then, the laws of each 

 separate cause which takes a share in 

 producing the effect is the first de- 

 sideratum of the Deductive Method. 

 To know what the causes are which 

 must be subjected to this process of 

 study may or may not be difficult 



number of instances to be consistent with 

 their having been recorded with due pre- 

 cautions. Whoever has carefully examined 

 any of the attempts continually made to 

 prove economic doctrines by such a recital 

 of instances, knows well )iow futile they 

 are. It always turns out that the circum- 

 stances of scarcely any of the cases have 

 been fully stated : and that cases, in equal 

 or greater numbers, have been omitted, 

 which would have tended to an opposite 

 conclusion. 



