I 4 2 THE SCIENCE OF LOGIC 



explain the facts ; all we can say of some of them is that they 

 explain the facts more satisfactorily than any alternative hypo 

 theses so far suggested ; and if we find an hypothesis which was 

 conceived in explanation of one group of phenomena to be 

 capable of extension to many other cognate groups, and to explain 

 these satisfactorily also, such &quot; consilience of inductions &quot; may 

 make us morally certain that our hypothesis is the right one. 



Our verification of such hypotheses will consist in our pointing to their 

 superior power of explaining facts. It is well to emphasize this point ; because, 

 firstly, it is with the validity of these wider and more general hypotheses that 

 philosophy, as distinct from the special sciences, is mainly concerned ; and 

 because, in the second place, the special sciences are full of them. As Mr. 

 Joseph rightly observes : &quot; many at least of the most general and fundamental 

 of our scientific principles are accepted only because they explain the facts of 

 our experience better than any we can conceive in their stead ; they are there 

 fore, or were at the outset, hypotheses, used in explanation of facts, and proved 

 by their relative success in explaining them. We do not see why they are 

 true, but only why we must believe them to be true. They are established 

 inductively by the facts which they explain, and the failure of any rival hypo 

 thesis ; the facts are explained from them &quot;- 1 Now are we to regard such 

 hypotheses as proved or -verified, because they explain the facts &quot; better than 

 any we can conceive in their stead &quot; ? Mr. Joseph adds : &quot; it is important to 

 realize that an hypothesis is not really proved by merely explaining the facts. 

 But many hypotheses are provisionally accepted, which are not proved, on the 

 ground that they explain the facts, and without the performance of what would 

 often be the impracticable task of showing that no other hypothesis could 

 equally well do so.&quot; 2 What kind and amount of credence, then, are we to 

 give to such hypotheses, the evidence for which is cumulative, though not 

 cogent ? This is an extremely delicate and difficult matter to determine ; and 

 all the more so because the hypotheses in question are usually of considerable 

 significance : they are the theories that shape men s convictions about the 

 ultimate causes and nature of the universe. Each such theory must be judged 

 on its merits ; and the responsibility of accepting or rejecting it, or holding it 

 provisionally, calls for the exercise of care, caution, and prudence. 



231 . POSTULATES &quot; AND THEIR JUSTIFICATION : &quot; TRUTH &quot; 

 OF VERIFIED HYPOTHESES. There can be no reasonable doubt 

 that this cumulative evidence may become sufficient to warrant 

 an assent of moral certitude to such a theory. But men differ so 

 much in their mental outlook on account of the different intel 

 lectual atmospheres, traditions, and beliefs, in which they have 

 lived and moved that evidence which may satisfy one will be 

 deemed insufficient by another. Hence the conflicting philoso- 



1 op. cit., pp. 476-7. Cf. MELLONE, op, cit., p. 332 : &quot; It is this demonstration 

 that the consequences of a law do actually agree with facts, that forms for science 

 the verification of that law &quot;. 



9 ibid., p. 477n. 



