SECT. 8.] Modality. 303 



express quite correctly, if the mere nature and not the 

 degree of that assent is taken into account, by saying that 

 he is likely to die. In this case the modality is rejected 

 temporarily from the premises to be reintroduced into the 

 conclusion. 



It is obvious that such a process as this is of a very 

 rough and imperfect kind. It does, in fact, omit from accu 

 rate consideration just the one point now under discussion. 

 It takes no account of the varying shades of expression by 

 which the degree of departure from perfect conviction is 

 indicated, which is of course the very thing with which 

 modality is intended to occupy itself. At best, therefore, it 

 could only claim to be an extremely rude way of deciding 

 questions, the accurate and scientific methods of treating 

 which are demanded of us. 



8. In any employment of applied logic we have of 

 course to go through such a process as that just mentioned. 

 Outside of pure mathematics it can hardly ever be the case 

 that the premises from which we reason are held with abso 

 lute conviction. Hence there must be a lapse from absolute 

 conviction in the conclusion. But we reason on the hypo 

 thesis that the premises are true, and any trifling defection 

 from certainty, of which we may be conscious, is mentally 

 reserved as a qualification to the conclusion. But such con 

 siderations as these belong rather to ordinary applied logic ; 

 they amount to nothing more than a caution or hint to be 

 borne in mind when the rules of the syllogism, or of in 

 duction, are applied in practice. When, however, we are 

 treating of modality, the extent of the defection from full 

 certainty is supposed to be sufficiently great for our language 

 to indicate and appreciate it. What we then want is of 

 course a scientific discussion of the principles in accordance 

 with which this departure is to be measured and expressed, 



