6a THE SCIENCE OF LOGIC 



brings it about, which makes it happen, whether this cause be 

 free (i.e. self-determining) or not, in its mode of action. 



Now, induction being mainly concerned with the discovery 

 of the causes which bring about the phenomena that constitute 

 our experience, it is important to have a clear understanding in 

 the first place about what scientists, logicians, and philosophers 

 mean by a &quot; cause &quot;. 



What we may call the common and traditional notion of 

 &quot; cause &quot; is that of &quot;anything which contributes in any positive 

 way to the existence or happening of something else &quot;. Aristotle 

 distinguished between two intrinsic causes, the &quot; formal &quot; and the 

 &quot;material,&quot; which constituted that &quot;something,&quot; and two other 

 causes, the &quot;efficient&quot; and the &quot;final,&quot; extrinsic to the &quot;some 

 thing,&quot; and in regard to which the latter is properly called an 

 &quot; effect &quot;. The notions of &quot; formal &quot; and &quot; final &quot; causes are 

 closely connected with the Aristotelean view of nature as re 

 vealing Purpose and Design (217). We shall see that modern 

 science and philosophy are not the better for discarding these 

 notions. 1 Inductive logicians confine their attention almost ex 

 clusively to the study of efficient causality ; and of this many 

 have perverted, or rather abandoned, the traditional notion. 



The popular idea of &quot; efficient cause &quot; is that of an agent or 

 agency something which by means of perceptible action, motion, 

 or change, produces some new state or condition of things. Thus 

 understood, a cause is clearly distinguished from a condition ; the 

 latter being anything which, though necessary for the happening 

 of the effect, does not contribute positively thereto: windows, for 

 instance, being the condition, not the cause, of the daylight in a 

 room. Most logicians of induction, however, ignore this distinc 

 tion 2 : the reason being that, so far as physical science is concerned, 

 it is of no importance. Nor indeed is it, provided we assume 

 that the duty of the physical scientist as such is merely to discover 

 all the antecedents, positive and negative, of whatsoever sort, 

 which are sufficient and indispenable for the happening of any 

 given phenomenon, without troubling himself about the manner 

 in which they contribute thereto. 8 But not all are willing to set 

 such limits to the scope of physical science ; though, of course, 



1 Cf. VENN, Empirical Logic, pp. 47-62, as an example of the attitude of the 

 empirical school of logicians towards them. 



3 Cf. WELTON, op. cit. t ii., p. 19, where &quot; cause &quot; is defined as the &quot; totality of con 

 ditions &quot; requisite to the happening of a phenomenon. 



* Cf. JOYCB, Op. Cit., p. 221. 



