DEFINITION AND PROVINCE OF LOGIC. 3 



requii'ed for that pui-pose alone. INIorc recent Avi-iters on logic have 

 genei-ally understood the term as it was employed by the able authors 

 of the Port Royal Logic ; viz., as equivalent to the Art of Thinking. 

 Nor is this acceptation confined to philosophers, and works of science. 

 Even in conversation, the ideas usually connected with the word Logic, 

 include at least precision of language, and accuracy of classification : 

 and we perhaps oftener hear pei'sons speak of a logical arrangement, 

 or expressions logically defined, than of conclusions logically deduced 

 from premisses. Moreover, a man is often called a gi'cat logician, or a 

 man of powerful logic, not for the accuracy of his deductions, but for 

 the extent of his command over premisses ; because the general propo- 

 sitions required for explaining a difficulty or refuting a sophism, copi- 

 ously and promptly occur to him ; as in the case of Chillingworth, or 

 Samuel Johnson. Wliether, therefore, we conform to the jiractice of 

 those who have made the subject their particular study, or to that of 

 popular wi'iters and common discourse, the province of logic will 

 include several operations of the intellect not usually considei'ed to fall 

 within the meaning of the terms Reasoning and Argumentation. 



These various operations might be brought within the compass of the 

 science, and the additional advantage be obtained of a very simple 

 definition, if, by an extension of the term, sanctioned by high authori- 

 ties, we were to define logic as the science which treats of the opera- 

 tions of the human understanding in the pursuit of truth. For to this 

 ultimate end, naming, classification, definition, and all the other opera- 

 tions over which logic has ever claimed jurisdiction, are essentially 

 subsidiary. They may all be regarded as contrivances for enabling a 

 person to know the truths which are needful to him, and to know 

 them at the precise moment at which they are needful. Other pur- 

 poses, indeed, are also served by these operations ; for instance, that 

 of imparting our knowledge to others. But, viewed with regard to 

 this purpose, they have never been considered as within the province 

 of the logician. The sole object of Logic is the guidance of one's 

 own thoughts; the communication of those thouglits to others falls 

 under the consideration of Rhetoric, in the large sense in whicll that 

 art was conceived by the ancients ; or of the still more extensive art 

 of Education. Logic takes cognizance of all intellectual operations, 

 only as they conduce to our own knowledge, and to our command 

 (jver that knowledge for our own uses. If there ■u^ere but one rational 

 being in the universe, that being might be -a perfect logician ; and the 

 science and art of logic would be the same for that one person, as for 

 the whole human race* 



§ 4. But, if the definition which we formerly examined included too 

 little, that wliich is now suggested has the opposite fault of including 

 too much. 



Truths are known to us in two ways : Some are knOwn directly, 

 and of themselves ; some through the medium of other truths. The 

 former are the subject of Intuition, or Consciousness ; the latter, of 

 Inference. The truths known by intuition are the original premisses 

 from which all others are inferred. Our assent ta the cpnclusion 

 being grounded upon the truth of the premisses, we never could amve 

 at any knowledge by reasoning, unless something could be known 

 antecedently to all reasoning. 



