CHAPTER III. 

 FIGURES AND MOODS OF THE SYLLOGISM. 



159. DISTINCTION OF FIGURES. By the figure of a syllogism 

 we understand the position of the middle term relatively to the ex 

 tremes in the premisses. Distinctions of figure result, therefore, 

 from a consideration of the position of the terms of the syllogism 

 its remote matter in its premisses. 



Thus, the middle term may be subject in one premiss and 

 predicate in the other ; it may be predicate in both ; or it may 

 be subject in both. And, if we distinguish between major and 

 minor premiss (148), the first of these three alternatives involves, 

 theoretically at least, two distinct cases : that in which the middle 

 term is subject in the major and predicate in the minor premiss, 

 and that in which the middle term is predicate in the major and 

 subject in the minor premiss. The former of these two cases 

 gives us the First (or &quot; Perfect &quot; Aristotelean) Figure ; the latter 

 gives us the so-called Fourth (or &quot; Galenian &quot;) Figure, or else 

 what Aristotle recognized and as an indirect and less natural 

 mode of drawing a conclusion in the first figure a conclusion 

 about what is naturally the major extreme (78, 148), in terms 

 of the minor extreme (171). The case in which the middle term 

 is twice predicate gives us the Second Figure ; that in which the 

 middle term is twice subject gives us the Third Figure. Thus 

 we have the following empty schemes of the four figures : 

 Fig. I. Fig. II. Fig. III. Fig. IV. 



MP PM MP PM 



SM SM MS MS 



... ~s~p~ .-. SP .-. SP .*. SP 

 For these we have the mnemonic line of Scholastic logic : 

 &quot; Sub. prae. PRIM A ; ALTER A bis prae. ; TERTIA bis sub ; (to 

 which we might add : QuARTA/ra*. sub.}. 



I . M is subject of the major and predicate of the minor pre 

 miss in the FIRST FIGURE ; 



319 



