. , 



, 3$ THE SCIENCE OF LOGIC. 



^far concerning its nature and scope, its subject-matter and divi 

 sions, its formal object and its relations to certain other sciences, 

 we are now in a position to attempt a definition of logic. Many 

 definitions have been proposed good, bad, and indifferent. 

 But a discussion of their relative merits and demerits would, at 

 the present stage of our inquiry, be neither profitable nor desir 

 able. Logic has been variously defined as the Art of Right 

 Thinking; the Art and Science of Right Reasoning ; \heArtoJ 

 Attaining Truth ; the Science of the Formal Laws of Thought ; 

 the Science of the Principles which Regulate Valid Thought ; the 

 Practical Science which Directs the Operations of the Mind towards 

 Truth ; etc. On the whole, we are inclined to prefer some defini 

 tion on the lines of the last just given. We would, therefore, 

 prefer to define the science of logic somewhat more explicitly as : 

 the Practical x Science which Directs our Mental Operations in the 

 Discovery and Proof of Truth. 



24. UTILITY AND NECESSITY OF LOGIC. It would be a 

 mistake to imagine that, above and beyond what is called the 

 Natural Logic of sound common sense, the study of the Science of 

 Logic is absolutely necessary for right reasoning. Men reasoned 

 rightly before Aristotle ever formulated a canon of logic. It 

 was, in fact, by an analysis of such reasonings that he discovered 

 those canons : they could never have been discovered otherwise. 

 Here as elsewhere the art came before the science ; theory fol 

 lowed practice. A man may reason rightly without knowing 

 a single rule of the syllogism ; or, conversely, he may know all 

 the details of logic and be an indifferent guide to truth just as 

 a first-rate geometrician may be a failure as an engineer. But 

 still, just as his knowledge of geometry will enable the geo 

 metrician to detect the defects in a piece of engineering, so too 

 will an explicit knowledge of the canons of reasoning enable 

 us to discover more readily where the fallacy of a misleading 

 argument lies. Without professing to guard us infallibly from 

 error, logic familiarizes us with the rules and canons to which 

 right reasoning processes must conform, and with the hidden 

 fallacies and pitfalls to which such processes are commonly ex 

 posed. 2 Hence one obvious benefit derivable from a careful 



1 i.e. including the theoretical groundwork (&quot; Logica Docens &quot;) on which the 

 actual exercise or art of correct thinking (&quot; Logica Utens &quot;) is based (8). 



2 &quot; A man who is very ready at integration begins to hesitate and flounder when 

 he is asked such a simple question as the following : If all triangles are plane 



