22 THE SCIENCE OF LOGIC. 



which they appear differently, than animal nature can be fully known without 

 attending to the different orders of animal in which it appears differently.&quot; l 



Notwithstanding the fact, therefore, that we can distinguish between the 

 matter and the form of thought, it is obviously impossible to think at all with 

 out thinking of something, to have the form without the matter of thought ; 

 and hence if we are to understand by a purely formal logic a science of the 

 Pure, empty, &quot; a priori &quot; forms of thought, i.e. forms devoid of all matter or con 

 tent and prior to all experience, such a science is impossible, for its object is 

 chimerical and unattainable. It is impossible to separate thought entirely 

 either from the things or objects to which it has reference or from the 

 language which is its expression. Hence to make logic purely subjective or 

 conceptual or formal excluding all reference to things and words is almost 

 as erroneous as to make it conversant with language only. Logic deals with 

 both language and things, though only indirectly : the former as expressive 

 of, the latter as represented in, and interpreted by, thought. 



But there is a sense in which we may perhaps admit the pos 

 sibility of a division of logic into a logic of consistency and a logic of 

 truth. Since it is true that we can distinguish between consistency 

 and truth we may distinguish the logical investigations which aim 

 at securing the former from those which aim at securing the latter ; 

 and in this sense we should distinguish the investigation of the 

 laws of all formally valid reasoning i.e. of reasoning that is con 

 sistent, or true hypothetically from practically all the remaining 

 sections of logical doctrine about conception, judgment, classifi 

 cation, induction, scientific explanation and proof: all of which 

 have in view not merely the subjective consistency but the objec 

 tive truth of our knowledge. 



Were we, however, to confine logic to an investigation of the 

 necessary and universal laws which secure mere consistency in 

 thought, we should bear in mind two things : firstly, that we must 

 make provision in some philosophical science for the adequate 

 treatment of the means and tests for securing truth, over and above 

 the laws that secure consistency (17); secondly, that even these latter 

 laws are not exclusively subjective or formal. This latter point 

 deserves attention. 



That there are such universal and necessary laws of thought is beyond 

 all dispute. That their necessity and universality arise exclusively from the 

 nature of the thinking subject and not at all from the nature of the object 

 thought about is a mistake. For, although the things about which we 

 think may differ very much from one another, yet they have something in 

 common : they are all things, realities. The laws revealed by logic as 

 underlying the consistency of thought derive their necessary and universal 



1 JOSEPH, Introduction to Logic, pp. 4-6 ; cf. ibid., pp. 339 sqq. 



