UNIFORMITY OF NATURE 95 



about any individual case. It &quot; supposes the First Cause to preserve 

 the ordinary operation of natural laws&quot;. 1 This supposition is expli 

 citly contained in the reference to &quot;similar circumstances&quot;. A 

 case of interference by the First Cause would alter the circum 

 stances. Such a case would not come under the principle. As 

 stated, therefore, the principle is a metaphysically necessary 

 one. It is, moreover, self-evident to anyone who understands 

 the import of the concepts involved in it. These, however, are com 

 plex concepts, and to acquire them is a work of time and experi 

 ence ; for which reason we may admit that the principle, even 

 understood hypothetically, is, to use the words of Mill, 2 &quot; by no 

 means one of the earliest which any of us ... can have&quot; reached. 

 It is a propositio per se nota in se (86). That is, it is an analytic, a 

 priori proposition, whose truth is grasped intuitively by the mind 

 as soon as the concepts involved in it are fully analysed and 

 juxtaposed in thought. But we may freely admit that it is not 

 a propositio per se nota quoad omnes, that it is not like &quot; two and 

 two are four &quot; immediately evident to everybody, because not 

 everybody has clear and definite notions about the nature of a 

 physical or non-free cause, its activity in similar conditions, and 

 uniformity of effect. 



We need to become familiar with the ordinary operations of 

 nature in order to conceive the notion of natural cause, i.e. of a 

 cause which is not free to determine itself- as the human will does 

 to produce this, that, or the other effect : a cause which has one 

 definite, fixed line of action, one stable tendency which it endea 

 vours as it were to realize and satisfy by its action. But, as soon 

 as a person has formed, from his experience of the uniform re 

 currence of natural phenomena, the idea of a &quot;physical or natural 

 cause or agent, acLing repeatedly in similar sets of circumstances&quot; he 

 will see intuitively, by an analysis of that concept, and comparison 

 with the concept of &quot;uniform production of the same effect&quot; a 

 metaphysically necessary connexion between them. 



The principle of uniformity, understood in this hypothetical or 

 formal sense, is, however, nothing more than a purely formal 

 generalization of an abstract judgment, which prescinds from the 

 actual existence or occurrence of any such entity as a &quot;physical 

 or non-free cause &quot;. It does not imply that there are such causes 

 in existence, nor that they act repeatedly in similar circumstances, 



1 JOYCE, op. cit., p. 238. 2 Logic, III., xxi., 2. 



