TEHZEEB UL MANTIK. QQ 



gation, there is indispensibly required some general 

 rule to preserve the mind from faUing into an error 

 in the process of thinking. This rule is logic. 



From this discussion, therefore, it appears that the 

 Nature of logic may be defined " A general rule 

 which oruards the mind against errors in thinkipo-." 



But in the language of logicians, thinking is an 

 arrangement of certain things known, to obtain a 

 knowlege of things unknown. Consequently the end 

 or use of logic likewise becomes obvious and mani- 

 fest. 



There now remains to be examined, only the sub" 

 ject of logic ; and this is the known perceptible and 

 the known demonstrable, in such a form as to lead 

 to the unknown perceptible and unknown demon- 

 strable. The first of these is called definUioii ; the 

 second demonstration or proof. '* The idea of an 

 animal endowed with the faculty of speech," leading 

 to the idea of man, is an example of definition. The 

 proposition, '* The world is liable to change, and 

 every thing liable to change is created," leading to 

 the conclusion " that the world was created," exhi- 

 bits an example of demonstration. 



PART I. Of Definition. 



Sect. I. Op Expression. 



Expression in the technical language of logi- 

 cians, is the existence of a thing in such general use, 

 that there necessarily or irresistibly arises from the 

 knowledge of that tiling the knowledge of another 

 thing. The first they call the Sign, the second 

 the thing signified. If the sign be a word, they call 

 it verbal expression ; and if not a word, they call it 

 expression not verbal ; and these two together com- 

 prehend six different distinctions ; ] . Assigned ex- 

 pression verbal ; 2. Assigned expression not verbal ; 



H2. 



