SECT. 5.] Modality. 299 



what is meant by a modal predicate, by the predicate 

 probably mortal, for instance, in the proposition All poison 

 ings by arsenic are probably mortal ? If the analogy with 

 ordinary pure propositions is to hold good, it must be a 

 predicate referring to the whole of the subject, for the sub 

 ject is distributed. But then we are at once launched into 

 the difficulties discussed in a former chapter (Ch. vi. 19 

 25), when we attempt to justify or verify the application of 

 the predicate. We have to enquire (at least on the view 

 adopted in this work) whether the application of the pre 

 dicate probably mortal to the whole of the subject, really 

 means at bottom anything else than that the predicate 

 mortal is to be applied to a portion (more than half) of the 

 members denoted by the subject. When the transference of 

 the modality to the predicate raises such intricate questions 

 as to the sense in which the predicate is to be interpreted, 

 there is surely nothing gained by the step. 



5. A second, and more summary way of shelving all 

 difficulties of the subject, so far at least as logic, or the 

 writers upon logic, are concerned, is found by simply denying 

 that modality has any connection whatever with logic. This 

 is the course adopted by many modern writers, for instance, 

 by Hamilton and Mansel, in reference to whom one cannot 

 help remarking that an unduly large portion of their logical 

 writings seems occupied with telling us what does not belong 

 to logic. They justify their rejection on the ground that 

 the mode belongs to the matter, and must be determined by 

 a consideration of the matter, and therefore is extralogical. 

 To a certain extent I agree with their grounds of rejection, 

 for (as explained in Chapter vi.) it is not easy to see how 

 the degree of modality of any proposition, whether premise 

 or conclusion, can be justified without appeal to the matter. 

 But then questions of justification, in any adequate sense of 



