228 REASONING. 



FOURTH FIGURE. 



All C is B All C is B Some C is B No C is B No C is B 



All B is A No B is A All B is A All B is A Some B is A 



therefore therefore therefore therefore therefore 



Some A is C Some A is C Some A is C Some A is not C Some A is not C 



In these exemplars, or blank forms for making 

 syllogisms, no place is assigned to singular propo- 

 sitions ; not, of course, because such propositions are 

 not used in ratiocination, but because, their predicate 

 being affirmed or denied of the whole of the subject, 

 they are ranked, for the purposes of the syllogism, 

 with universal propositions. Thus, these two syllo- 

 gisms 



All men are mortal, All men are mortal, 



All kings are men, Socrates is a man, 



therefore therefore 



All kings are mortal, Socrates is mortal, 



are arguments precisely similar, and are both ranked 

 in the first mode of the first figure. 



The reasons why syllogisms in any of the above 

 forms are legitimate, that is, why, if the premisses be 

 true, the conclusion must necessarily be so, and why 

 this is not the case in any other possible mode, that 

 is, in any other combination of universal and par- 

 ticular, affirmative and negative propositions, any 

 person taking interest in these inquiries may be pre- 

 sumed to have either learnt from the common school 

 books of the syllogistic logic, or to be capable of 

 divining for himself. The reader may, however, be 

 referred, for every needful explanation, to Archbishop 

 Whately's Elements of Logic, where he will find 

 stated with philosophical precision, and explained 

 with peculiar perspicuity, the whole of the common 

 doctrine of the syllogism. 



