UNIFORMITY OF NATURE 97 



will act uniformly&quot; goes distinctly farther than the hypothetical 

 principle that &quot; if a cause is faced necessarily to one mode of action 

 it will act uniformly in similar circumstances&quot;. Yet those two 

 distinct and separate statements are sometimes identified, or rather 

 confounded, under the common designation of the &quot; uniformity ot 

 nature &quot;. And those who rightly distinguish between them 

 usually limit the latter title to the abstract, hypothetical principle, 

 describing the categorical assertion as belief 1 &quot; in the maintenance 

 of the present order of things in the universe &quot;. Thus Dr. Mellone, 

 in his Introductory Text-Book of Logic? draws &quot;an important dis 

 tinction between two meanings of the uniformity of nature: (i) 

 the uniformity of causation, (2) the maintenance of the present 

 order of things in the universe. Experience [he continues] shows 

 us that there are general laws i.e. kinds of orderly succes 

 sion in the outward course of events : such as appear in the suc 

 cession of day and night, summer and winter, seed-time and 

 harvest, life and death. The regular succession of events in a 

 thousand different ways accustoms us, from force of habit, to ex 

 pect things to happen in a regular order ; and we find that the 

 expectation is fulfilled. This constitutes an overwhelming pre 

 sumption in favour of the maintenance of the present arrangements 

 in nature ; but it does not show that derivations from this order 

 are impossible. An expectation, bred by experience and custom, 

 that events will occur in a certain way is not the same as a know 

 ledge that they must so occur ; and this knowledge is not in our 

 possession. We have no grounds for affirming that the sun must 

 rise to-morrow morning ; there is only an overwhelming presump 

 tion in favour of the expectation that it will. But the principle 

 of uniform causation tells us nothing as to the permanence of the 

 present choir of heaven and furniture of earth . It only says 

 that the same cause will have the same effect ; and to this there 

 are no exceptions. The same cause may conceivably never act 

 again ; but this does not affect the truth of the principle that if 

 it did it would have the same effect &quot;. 



But, then, is the inductive process, by which we establish a 

 law of physical nature (&quot;IfS is M it is P&quot; : &quot;Ifa bar of iron 

 be heated it will be elongated&quot;}, an application merely of the 



1 This &quot; belief&quot; extends to the past no less than to the future, to the distant as 

 well as to the near ; it is a conviction which has for its object the existence and opera 

 tion, throughout time and space, of natural or necessitating causes, 



2 pp. 281-2. 



VOL. II. 7 



