CONCEPTS OF REASON &quot; AND &quot; C4 i/5^ 1 &quot; 61 



progress in knowledge without the aid of such an assumption ; and, besides, 

 there is at least this other alternative postulate the postulate of Theism that 

 the sense world reveals itself to the human intellect not as the self-evolution, 

 at once logical and real, of a Sole Being that is at once thought and reality, 

 but, rather, as a distinct system, dependent no less on a Supreme Will for its 

 actuality than on a Supreme Intelligence for its intelligibility. 



This, then, is another possible alternative, and it is the true one : that the 

 whole world of human experience (including the human mind itself) is the 

 creation of a Supreme Free Will, governed by laws laid down by a Supreme 

 Intelligence {Philosophy of Theism] ; and not the logically necessary unfold 

 ing or evolution of one Sole Idea-Being (Idealistic Pantheism) ; or the ob 

 verse and unknowable background of the transient panorama which con 

 stitutes the individual man s sense consciousness (Empiricism, Agnosticism). 



These are three alternative points of view there are others also from 

 which individual writers on inductive logic may proceed to lay down principles 

 for the guidance of the student in his search after truth, whether in science, in 

 philosophy, or in theology. The differences between them are revealed in the 

 respective ways in which writers of each of these schools treat of causality, 

 hypothesis, and generalization (based on the law of Nature s Uniformity), as 

 well as in the different ideals they set up regarding Scientific Explanation and 

 Physical Certitude. In the chapters that follow, we shall, therefore, have oc. 

 casion to recur repeatedly to the views we have just mentioned ; and the 

 principle itself of sufficient reason will arise again explicitly, in connexion with 

 the theory of Demonstration and Scientific Explanation. 



2 1 6. THE PRINCIPLE OF CAUSALITY IN INDUCTION: ARIS 

 TOTLE S CLASSIFICATION OF CAUSES. When applied to contin 

 gent things, to the phenomena of nature around us, the principle 

 of sufficient reason resolves itself into the Principle of Causality. 

 This latter is an a priori, self-evident principle, like the former. 

 Cause and effect being correlative, to say that &quot; Every effect has 

 a cause&quot; is to state a truism. The principle is usually stated 

 thus : &quot; Whatever happens (occurs, takes place, begins to be) 

 has a cause &quot;. The axiom Ex nihilo nihil fit is a negative 

 statement of the same principle. And another statement of it, 

 &quot;Whatever is contingent (i.e. whatever does not contain in itself, 

 in its own essence, the sufficient reason of its actual existence) 

 has a cause,&quot; shows the connexion of the principle of causality 

 with the principle of sufficient reason. Being that is necessary 

 and self-existent has no cause. It is itself the reason of its own 

 existence ; whereas all contingent being is caused. The principle 

 of causality is evidently a necessary principle in regard to con 

 tingent being, i.e. it is essentially involved in our very concept 

 of contingent being. Nothing can happen without a cause: 

 whatever happens has necessarily a cause, i.e. something which 



