BOOK I. 



OF NAMES AND PROPOSITIONS. 



"La scolastique, qui produisit dans la logique, comme dans la morale, et dans une partie 

 de la metaphysique, une subtilite, une precision d'idees, dont I'habitude inconnue aux anciens, 

 a contribue' plus qu'on ne croit au pvogves de la bonne philosophie." — Condorcet, Vie de 

 Turcot. 



"To the schoolmen the vulgar languages are principally indebted for what precision and 

 analytic subtlety they possess. " — Sir W. Hamilton, Uiscmsions in Philosophy. 



CHAPTER I. 



OF THE NECESSITY OF COMMENCHSTG WITH AN ANALYSIS OF LANGUAGE. 



§ 1. It is so much the established practice of writers on logic to com- 

 mence their treatises by a few general obsei"vations (in most cases, it is 

 true, rather meagre) on Terms and their varieties, that it will, perhaps, 

 scarcely be required from me, in merely following the common usage, to be 

 as particular in assigning my reasons, as it is usually expected that those 

 should be who deviate from it. 



The practice, indeed, is recommended by considerations far too obvious 

 to require a formal justification. Logic is a portion of the Art of Think- 

 ing: Language is evidently, and by the admission of all philosophers, one 

 of the principal instruments or helps of thought; and any imperfection in 

 the instrument, or in the mode of employing it, is confessedly liable, still 

 more than in almost any other art, to confuse and impede the process, and 

 destroy all ground of confidence in the result. For a mind not previously 

 versed in the meaning and right use of the various kinds of words, to at- 

 tempt the study of methods of philosophizing, would be as if some one 

 should attempt to become an astronomical observer, having never learned to 

 adjust the focal distance of his optical instruments so as to see distinctly. 



Since Reasoning, or Inference, the principal subject of logic, is an opera- 

 tion which usually takes place by means of words, and in complicated cases 

 can take place in no^ other way ; those who have not a thorough insight 

 into the signification and purposes of words, will be under chances, amount- 

 ing almost to certainty, of reasoning or inferring incorrectly. And logi- 

 cians have generally felt that unless, in the very first stage, they removed 

 this source of error ; unless they taught their pupil to put away the glasses 

 which distort the object, and to use those which are adapted to his pur- 

 pose in such a manner as to assist, not perplex, his vision ; he would not be 

 in a condition to practice the remaining part of their discipline with any 

 prospect of advantage. Therefore it is that an inquiry into language, so 

 far as is needful to guard against the errors to which it gives rise, has at 

 all times been deemed a necessary preliminary to the study of logic. 



