70 THE SCIENCE OF LOGIC 



Writers who support this latter view bring out very clearly the shortcomings of 

 Empiricism ; l but, though they rightly include the concept of &quot; final cause &quot; i.e. 

 of purpose, design, in their philosophical explanation of natural phenomena, 

 they still fail to recognize explicitly the &quot; formal &quot; and &quot; material &quot; causes, as 

 distinct from the &quot;efficient causes,&quot; of phenomena, and are thus led to 

 identify the cause with the process, and this latter with the effect. 



In most of the physical sciences we are mainly concerned with the dis 

 covery and explanation of processes, changes, motions, activities, actions and 

 interactions between material agencies : and our main concern here must be 

 to find out what are the proximate agencies at work in a given process, to 

 separate these from irrelevant and accidental surroundings, to detect the total 

 (proximate) agens and the total (proximate) pattens in question, and to discover 

 and understand the connexion of physical efficient causality between these. 



But the discovery of a connexion of efficient causality, of action and 

 interaction, between physical agents, is the discovery of active and passive 

 powers or properties in these agents : and the discovery of such properties or 

 powers leads to a knowledge of the intrinsic constitution, the nature, of these 

 agents. As a thing acts, so it is : Qua/is operatic, talis natura. All the 

 insight we have into the inner nature and constitution of things is got by 

 inference from their observed activities : Operari sequitur esse. And our 

 knowledge of the inner nature and constitution of a physical cause, of the 

 manner and conditions of its activities, will help us to understand its raison 

 d etre, its function or role in the universe, the purpose it serves, the end it is 

 designed to fulfil, the final cause of the processes in which it plays a part. 



Thus we see that the search for any one class of cause is by no means 

 incompatible with a search for the others. When one line of inquiry cannot 

 be prosecuted, another may ; and each often helps the others. 



2 1 8. CONTRAST BETWEEN TRADITIONAL AND EMPIRICAL 

 CONCEPTIONS OF EFFICIENT CAUSALITY. When the word 

 &quot;cause&quot; is used without qualification &quot;efficient cause&quot; is meant. 

 Used in this sense, the term &quot; cause &quot; has almost completely changed 

 its traditional signification ; and with very confusing results. 

 We must, therefore, note these changes of meaning carefully. 



The traditional notion of efficient cause is that of &quot; anything 

 which positively contributes by way of action or change or motion 

 to the production or happening or existence of anything else&quot;. 

 Positive influence by way of action is what we mean by the &quot;effici 

 ency &quot; of a cause. This traditional conception of efficiency, or 

 efficient causality, we can find no reason or justification for abandon 

 ing. We shall therefore retain it. Furthermore, we must dis 

 tinguish between the individual, substantial cause or agent itself 

 (&quot; the agens&quot; the &quot; principium quod agit &quot;) ; the power, faculty, 

 force, potential energy, of that cause (the &quot;principium quo agens 

 agit&quot;); and the action (&quot;actio&quot;) by which it produces its effect. 



1 Cf. Professor WELTON S criticisms of Mill, op. cit., passim. 



