264 INDUCTION. 



notnena resulting from the composition of many causes, being from the 

 very nature of the case, inefficient and ilkisory ; there remains only 

 the third — that which considers the causes separately, atid computes 

 the effect from the balance of ^ the different tendencies which produce 

 it : in short, the deductive, or a priori method. The more particular 

 consideration of this intellectual process requires a chapter to it8el£ 



CHAPTER XI. 



OF THE DEDUCTIVE METHOD. 



§ 1. The mode of investigation which, from the proved inapplicability 

 of direct methods of observation ahd experiment, remains to us as the 

 mahi source of the knowledge we possess, or can acquire, respecting 

 the conditions, and laws of recuiTence, of the more complex phenom- 

 ena, is called in its most general expression, the Deductive Method; 

 and consists of three operations : the first, one of direct induction ; the 

 second, of ratiocination ; and 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 ; although 

 in many particular investigations the place of the induction may be 

 supplied by a prior deduction ; but the premisses of this prior deduc- 

 tion must have been derived from induction. 



The problem of the Deductive Method is, to find the law of an effect 

 from the laws of the different tendencies 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 

 premisses upon observation or experiment. Thus, if the subject be 

 social, or historical phenomena, the premisses of the Deductive Method 

 must be the laws of the causes which determine that class of phenom- 

 ena ; and those causes are human actions, together with the general 

 outward circumstances under the dominion of which mankind are 

 placed, and which constitute man's position in this, world. The -De- 

 ductive Method, applied to social phenomena, must begin, therefore, 

 by investigating, or must suppose to have been already investigated, 

 the laws of human action, and those properties of outward things by 

 which the actions 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 a,lways, and necessarily have been ob- 

 tained by a directly inductive process. 



To ascertain, then, the laws of each separate cause which takes a 

 share in producing the effect, is the first desideratum of the Deductive 

 Method. To know what the causes are, which must be subjected te 

 this process of study, may or may not be difficult. In the case last 

 mentioned, this first condition is of easy fulfilment. That social ph&. 

 nomena depended upon the acts and mental impressions of humaij 



