322 Modality. [CHAP. xm. 



It is doubtless true, that if the old logicians had been 

 in possession of such premises as modern Probability is con 

 cerned with, and had adhered to their own way of treating 

 them, they would have had to place them amongst such loci, 

 and thus to make the consideration of them a part of their 

 Dialectic. But inasmuch as there does not seem to have 

 been the slightest attempt on their part to do more here 

 than recognize the fact of the premises being probable ; that 

 is, since it was not attempted to measure their probability 

 and that of the conclusion, I cannot but regard this part of 

 Logic as having only the very slightest relation to Proba 

 bility as now conceived. It seems to me little more than 

 one of the ways (described at the commencement of this 

 chapter) by which the problem of Modality is not indeed re 

 jected, but practically evaded. 



27. As Logic is not the only science which is directly 

 and prominently occupied with questions about belief and 

 evidence, so the difficulties which have arisen there have 

 been by no means unknown elsewhere. In respect of the 

 modals, this seems to have been manifestly the case in Juris 

 prudence. Some remarks, therefore, may be conveniently 

 made here upon this application of the subject, though of 

 course with the brevity suitable on the part of a layman who 

 has to touch upon professional topics. 



Recall for a moment what are the essentials of modality. 

 These I understand to be the attempt to mark off from one 

 another, without any resort to numerical notation, varying 

 degrees of conviction or belief, and to determine the conse 

 quent effect of premises, thus affected, upon our conclusions. 

 Moreover, as we cannot construct or retain a scale of any 

 kind without employing a standard from and by which to 

 measure it, the attainment and recognition of a standard of 

 certainty, or of one of the other degrees of conviction, is 



