FUNCTIONS AND VALUE OF THE SYLLOGISM. 245 



so explicitly made, has not prevented one set of 

 writers from continuing to represent the syllogism 

 as the correct analysis of what the mind actually 

 performs in discovering and proving the larger half of 

 the truths, whether of science or of daily life, which 

 we believe ; while those who have avoided this incon- 

 sistency, and followed out the general theorem 

 respecting the logical value of the syllogism to its 

 legitimate corollary, have been led to impute useless- 

 ness and frivolity to the syllogistic theory itself, on 

 the ground of the petitio principii which they allege 

 to be inherent in every syllogism. As I believe both 

 these opinions to be fundamentally erroneous, I must 

 request the attention of the reader to certain consi- 

 derations, without which any just appreciation of the 

 true character of the syllogism, and the functions it 

 performs in philosophy, appears to me impossible; 

 but which seem to have been either overlooked, or 

 insufficiently adverted to, both by the defenders of 

 the syllogistic theory and by its assailants. 



2. It must be granted that in every syllogism, 

 considered as an argument to prove the conclusion, 

 there is a petitio principii. When we say, 



All men are mortal 

 Socrates is a man 



therefore 

 Socrates is mortal ; 



it is unanswerably urged by the adversaries of the 

 syllogistic theory, that the proposition, Socrates is 

 mortal, is presupposed in the more general assump- 

 tion, All men are mortal : that we cannot be assured 

 of the mortality of all men, unless we were previously 

 certain of the mortality of every individual man : that 



