318 Modality. [CHAP. xni. 



precise arithmetical expressions of Probability, the question 

 still remains whether what may be termed our popular modal 

 expressions could not be improved and adapted to more 

 accurate use. It is true that the attempt to separate them 

 from one another by any fundamental distinctions is futile, 

 for the magnitude of which they take cognizance is, as we 

 have remarked, continuous ; but considering the enormous 

 importance of accurate terminology, and of recognizing 

 numerical distinctions wherever possible, it would be a real 

 advance if any agreement could be arrived at with regard to 

 the use of modal expressions. We have already noticed (ch. 

 II. 16) some suggestions by Mr Galton as to the possibility 

 of a natural system of classification, resting upon the regu 

 larity with which most kinds of magnitudes tend to group 

 themselves about a mean. It might be proposed, for in 

 stance, that we should agree to apply the term good 

 to the first quarter, measuring from the best downwards ; 

 * indifferent to the middle half, and bad to the last quarter. 

 There seems no reason why a similarly improved terminology 

 should not some day be introduced into the ordinary modal 

 language of common life. It might be agreed, for instance, 

 that very improbable should as far as possible be confined 

 to those events which had odds of (say) more than 99 to 1 

 against them ; and so on, with other similar expressions. 

 There would, no doubt, be difficulties in the way, for in all 

 applications of classification we have to surmount the two 

 fold obstacles which lie in the way, firstly (to use Kant s 

 expression) of the faculty of making rules, and secondly of 

 that of subsumption under rules. That is to say, even if we 

 had agreed upon our classes, there would still be much doubt 

 and dispute, in the case of things which did not readily lend 

 themselves to be counted or measured, as to whether the 

 odds were more or less than the assigned quantity. 



