226 ARISTOTELIAN LOGIC. [CHAP. XV. 



CHAPTER XV. 



THE ARISTOTELIAN LOGIC AND ITS MODERN EXTENSIONS, EX- 

 AMINED BY THE METHOD OF THIS TREATISE. 



1. HPHE logical system of Aristotle, modified in its details, 

 -- but unchanged in its essential features, occupies [so im- 

 portant a place in academical education, that some account of its 

 nature, and some brief discussion of the leading problems which 

 it presents, seem to be called for in the present work. It is, I 

 trust, in no narrow or harshly critical spirit that I approach this 

 task. My object, indeed, is not to institute any direct compa- 

 rison between the time-honoured system of the schools and that 

 of the present treatise ; but, setting truth above all other con- 

 siderations, to endeavour to exhibit the real nature of the ancient 

 doctrine, and to remove one or two prevailing misapprehensions 

 respecting its extent and sufficiency. 



That which may be regarded as essential in the spirit and 

 procedure of the Aristotelian, and of all cognate systems of Logic, 

 is the attempted classification of the allowable forms of inference, 

 and the distinct reference of those forms, collectively or indivi- 

 dually, to some general principle of an axiomatic nature, such as 

 the " dictum of Aristotle :" Whatsoever is affirmed or denied of 

 the genus may in the same sense be affirmed or denied of any 

 species included under that genus. Concerning such general 

 principles it may, I think, be observed, that they either state di- 

 rectly, but in an abstract form, the argument which they are 

 supposed to elucidate, and, so stating that argument, affirm its 

 validity ; or involve in their expression technical terms which, 

 after definition, conduct us again to the same point, viz., 

 the abstract statement of the supposed allowable forms of in- 

 ference. The idea of classification is thus a pervading element 

 in those systems. Furthermore, they exhibit Logic as resolvable 

 into two great branches, the one of which is occupied with the 

 treatment of categorical, the other with that of hypothetical or 



