26 THE SCIENCE OF LOGIC 



are concerned are just as really and truly discovered by us in 

 Nature, i.e. in the world revealed to our senses, as our &quot; physical&quot; 

 definitions, our concepts of the nature and activities of physical 

 agencies, are. They represent reality just as surely as the latter 

 do. The &quot; abstract objects &quot; which they define are really em 

 bodied in the world that is revealed to our senses, i.e. in the 

 physical universe. These objects and these definitions are not 

 arbitrary creations of our minds, fictions which we may modify at 

 will. If they were so, the pure deductive sciences would give us 

 no knowledge about reality, no real knowledge : they would be a 

 mere dream about the unreal. 



Besides the analytic, absolutely necessary, and universal 

 judgments we have just examined, there are, secondly, those that 

 we have called physically necessary and universal, and thirdly, 

 those that we have described as morally necessary and uni 

 versal. The judgments of these two latter classes are syn 

 thetic ; and it is the process by which we reach these more 

 especially the physical truths or laws (201) that most properly 

 deserves the name of &quot; induction &quot; or &quot; physical induction &quot;. 

 The discovery and proof of such laws is the aim of all 

 the physical, natural, or positive sciences ; for in these laws lies 

 the explanation of the facts and phenomena of those vast domains 

 of sense experience. To determine the laws according to which 

 those phenomena happen ; to get at the nature of the things of 

 experience ; to understand phenomena by the laws that govern 

 them, and individual things by the natures which abide and act in 

 them : such is the ambition of the physical scientist. He sets out 

 from the observation of complex, varying phenomena, to extract 

 from them their common principles and abiding laws : his work 

 is mainly a work of decomposing, dividing, analysing : his method 

 is called analytic ; and his whole process of ascent from particular 

 facts to general laws is called &quot; scientific&quot; or &quot;physical&quot; Induction. 



The doctrine of induction has been developed from, and largely based 

 upon, the remarkable growth of knowledge which the last few centuries have 

 witnessed in the physical sciences. In these sciences, especially, it finds its 

 application. From them, therefore, it naturally draws its aptest illustrations, 

 and we need not be surprised to find treatises on inductive logic often read 

 like pages from a handbook on some natural science (201). Nevertheless, it 

 is important to remember that induction is equally applicable to the data of 

 the social, anthropological, and philosophical sciences, as well as to physics : 

 and, moreover, it is only in so far as it is thus universally applicable that it 

 falls strictly within the scope of logic. 



