84 THE SCIENCE OF LOGIC 



recommend it (217). It explains nothing adequately ; and it is in fact rejected 

 as inadequate by the author himself in a subsequent chapter of his logic. 1 



221. &quot; PLURALITY OF CAUSES &quot; : &quot; RECIPROCAL &quot; AND &quot; NON- 

 RECIPROCAL&quot; CAUSAL RELATIONS. We have seen, so far, that 

 the term &quot; cause &quot; has a multiplicity of kindred meanings : that 

 besides the &quot; formal &quot; and &quot; material &quot; causes, or intrinsic consti 

 tutive principles of the visible, material agencies in nature, and 

 besides the &quot; final &quot; causes, &quot; ends &quot; or &quot; purposes &quot; for which 

 these act, there are also these agents themselves, which we have 

 called efficient &quot; causes. We have distinguished between these 

 efficient causes and the &quot; action &quot; or &quot; motion &quot; or &quot; process &quot; by 

 which they produce their effects. We have also distinguished 

 between efficient causes that are &quot; free &quot; or &quot; self-determining &quot; 

 and efficient causes that are &quot; necessary &quot; or &quot; necessitating &quot; ; and 

 we have seen that we can lay down general propositions about 

 the mode of operation of efficient causes throughout space and 

 time only in so far as we are convinced that those causes 

 act uniformly beyond the range of our own actual sense ex 

 perience (218); observing that this uniformity, though not 

 absent from the domain of free causes, is much more prevalent 

 and reliable in the domain of &quot; necessary &quot; causes that is, in the 

 physical sciences, with which induction is mainly concerned (218, 

 cf. 223). We have seen too that, generally speaking, every class 

 or kind of phenomenon in nature results from the convergence 

 and combination of numerous influences, agencies, and condi 

 tions, which are collectively &quot;sufficient&quot; (or &quot;necessitating&quot;) 

 and severally &quot;indispensable&quot; for the production of that special 

 kind of phenomenon (216). The multiplicity and variety of these 

 conditions, and their inseparable connexion with conditions not 

 needed for the production of this kind of phenomenon, render 

 it difficult for science to sift out and group together as the 

 &quot; cause&quot; of the phenomenon, just those influences and those only 

 which are sufficient and indispensable for its production. Com 

 bined with this difficulty of bringing to light the &quot; cause&quot; in this 

 narrower and stricter sense of reciprocal cause (cf. 213), we have 

 the consideration that from the practical point of view i.e. of 

 producing or preventing effects acquaintance with a plurality 

 of alternative &quot; causes,&quot; in the wider sense of &quot; sufficient &quot; though 

 not &quot;indispensable&quot; modes of producing that sort of effect, is 

 more important and more desirable than an exact knowledge of 

 1 op. cit., pp. 209, 210. Cf. JOSEPH, op. cit., p. 382. 



