Note 449 — Chapter IX

Bain (Logic, Deduction, p. 208) taking as an example the syllogism, “All men are mortal, All kings are men, therefore, All kings are mortal,” asks “Supposing there were any doubt as to the conclusion that kings are mortal, by what right do we proclaim, in the major, that all men are mortal, kings included?” He then continues, “In order to say, ‘All men are mortal,’ we must have found in some other way that all kings and all people are mortal. So that the conclusion first contributes its quota to the major premiss, and then takes it back again.” The reply to Bain’s challenge is that if we are in doubt as to whether kings are mortal, we may resolve our doubt by shewing that kings belong to a class the mortality of which is admitted. The question then resolves itself into whether it is possible to establish the mortality of mankind in general without any explicit consideration of the particular case of kings.