222 SCIENCE PROGRESS 



argue about propositions constructed with other verbs than " is " 

 and "are " ; whether we do not frequently argue and reason in 

 other ways than by including things in classes and excluding 

 things from classes. 



The stranger to Logic will naturally ask how it is that pre- 

 sumptions so remarkable, so easily examined, and so easily 

 refuted have remained unquestioned for two thousand years. 

 Is it not true that during that time Logic has been studied by 

 some of the acutest and profoundest thinkers that the human 

 race has produced ? and is not this prima-facie evidence that 

 they are right ? To this I reply at once, Yes, this does afford 

 prima-facie evidence, but prima-facie evidence is not proof. It 

 is open to refutation if reasons can be adduced against it ; and 

 surely, of all sciences, Logic should be the least afraid of an 

 appeal to reason. But it is afraid. The fabric of Logic will 

 hold together if, and only if, its presumptions are admitted 

 without question. They always have been admitted without 

 question; and thus is its long life explained. The efforts of 

 logicians, however acute and however distinguished, have been 

 devoted entirely to elaborating the fabric of Logic that has been 

 built upon certain foundations. The foundations have never 

 been examined. The authority of Aristotle, who laid them, 

 has always over-awed every subsequent thinker, and to question 

 his authority has been held a kind of profanity. In making the 

 following remarks I shall be looked upon much as Tom Paine 

 was looked upon by our grandfathers, as a ribald infidel for 

 whom the rack and the stake would be too merciful. 



Aristotle was unquestionably an acute and original thinker, 

 and his researches into the processes of thought were remark- 

 able for the time at which he lived, and are perhaps the most 

 considerable that have ever been made by any one man ; but 

 even so, his researches did not go very far ; he was not always 

 right ; and in subsequent ages his doctrines have been so 

 corrupted and vitiated that if he could read a modern text-book 

 he would indignantly repudiate many that are attributed to 

 him. Nevertheless, so great is his authority that the text-books 

 accept with reverence not only what he said, but also what he is 

 said to have said. 



This partly explains the absence of any criticism of the 

 presumptions of Logic ; another part of the explanation is that 

 man has no natural or spontaneous tendency to examine his 



