GENERAL VIEW OF NATURE AND SCOPE OF LOGIC. 15 



tive if the knowledge is acquired for its own sake and has no im 

 mediate application to practical ends, no immediate influence on 

 conduct, no immediate utility for any ulterior object ; it ^practical 

 if the knowledge is acquired not so much for its own sake as with 

 a view to using it for some ulterior purpose to which it is imme 

 diately applicable : Finis speculativae, veritas ; finis operativae sive 

 practicae, actio. Manifestly this distinction is not a fundamental 

 one ; for, in so far as it springs, not from the motive entertained 

 in studying the science, but from the nature of the knowledge 

 acquired, it is merely a matter of degree, since all true knowledge 

 has, or can have, some practical influence on external conduct ; 

 and furthermore, it is one and the same mind, one and the same 

 reason, that acquires all science, whether speculative or practical ; 

 and, finally, even the most practical knowledge may be acquired 

 for the sake of its own truth, apart altogether from its ulterior 

 value, and will be, under this aspect, speculative. 



An art, according to the ordinary use of the term, is under 

 stood to mean a collection of practical rules or canons or precepts 

 for our guidance in the performance of some work, usually exter 

 nal : TTpda-o-ew, facere, faire, to make, machen ; not merely men 

 tal : Troielv, agere, agir, to do, thun. But it also commonly means 

 practical skill derived from experience in the application of those 

 principles or rules. The principles themselves are partly the fruit 

 of study like the truths of a science and partly of actual ex 

 perience itself. The main division of the arts is that into the^* 

 arts music, painting, sculpture, etc. and the various mechanical 

 arts and crafts. 



Now, manifestly, logic is a science, for it studies and analyses 

 our mental processes and teaches us a systematized body of truths 

 concerning those processes. It is even speculative in character, 

 both in so far as the knowledge yielded by such analysis is desir 

 able for its own sake, and inasmuch as even its practical aim is 

 precisely to secure that very object which all speculative science 

 aims at knowledge of the truth. This is St. Thomas s point of* 

 view when he writes : &quot; In speculativis alia rationalis scientia est 

 dialectica . . . et alia scientia demonstrativa &quot;. 1 



Since, however, the knowledge acquired, the truths brought 

 to light, by logic, are immediately applicable to the exercise of 

 thought ; since they are in the nature of canons for securing cor 

 rect thought, for avoiding and detecting inaccurate reasoning ; 



1 Summa Theol., 2* 2ae, q. 51, art. 2, ad. 3. 



