58 THE SCIENCE OF LOGIC 



215. &quot;REALITY&quot; AND THE &quot;PRINCIPLE OF SUFFICIENT 

 REASON V Among the presuppositions of induction, many 

 authors set down in the first place the Principle of Sufficient 

 Reason : that &quot; whatever is judged to be true must have a reason 

 in our thought for being so judged ; and whatever is or happens 

 in the real order must have a sufficient reason or cause for so 

 being or happening &quot;. As a matter of fact, this principle is a 

 presupposition not of induction alone, but of all search whatever 

 after truth. It simply postulates that reality is intelligible, and 

 its explanation attainable at least to some extent. Unless we 

 assume that we can discover truth, it is idle to seek for truth. 

 All actual search after truth presupposes that some truth can be 

 found, and the gradual discovery of truth justifies the assumption. 

 The postulate is, therefore, reasonable and necessary. But at the 

 outset its meaning is essentially vague, and it is only by progress 

 in the discovery of truth that we can gradually attach definite 

 meanings to the terms &quot;sufficient reason,&quot; &quot;intelligible,&quot; &quot;ex 

 planation,&quot; etc. 



The principle refers to two orders, the logical and the real. 

 In the logical order, the order of thought, the premisses are the 

 sufficient reason of the conclusion, the antecedent of the conse 

 quent, until finally we come to some antecedent which, being 

 self-evident, has the sufficient reason of its truth in itself; that 

 is, in the reality which the judgment in question interprets by 

 means of two concepts carrying in them the evident ground for 

 the relation which the mind sets up between them. So, too, in 

 the real order, in the order of things, everything that exists, 

 every fact that happens, must have a sufficient reason, either 

 beyond itself in that its happening or inception is the effect of a 

 cause distinct from it, or in itself in that it exists necessarily and 

 of itself , and is itself the explanation of its own existence. 



But the two orders of thought and reality are not mutually 

 isolated and independent: the &quot;objective evidence&quot; which is the 

 logical ground or reason of first principles, is simply REAL 

 BEING put into relation with the MlND. 2 &quot; Objectum Intellects 

 est Ens&quot;: &quot;The object of Intellect is Reality&quot;. This maxim 

 of scholastic philosophy is the assertion, against subjective 



J C/. brochure entitled &quot; The Inductive Sciences : An Inquiry into some of their 

 Methods and Postulates&quot; by the present writer (Dublin : Browne & Nolan Ltd., 

 1910), pp. 10 sqq. 



3 i.e. ontological truth. C/. 248. 



