CONDITIONAL JUDGMENTS AND PROPOSITIONS 269 



cutting two parallel lines, etc. &quot;He may draw what straight lines and 

 angles he pleases, so it is uncertain what we may find drawn in any particular 

 case. We are therefore perfectly in order in employing the hypothetical 

 form and saying that if he draws such and such figures, such and such pro 

 perties will necessarily be found to be involved in them.&quot; l 



135. CONDITIONALS AND CATEGORICALS. The question 

 whether the same judgment may be expressed indifferently in 

 the conditional or in the categorical form, without any loss of, or 

 addition to, its meaning, has met with different solutions accord 

 ing to the various views adopted about the existential import, and 

 the modality, of these two forms. 



Were we to interpret the conditional form as always implying 

 a doubt about the occurrence of its antecedent, and the cate 

 gorical form as always implying certainty about the existence of 

 its subject, then, plainly, we could never lawfully pass from the 

 conditional to the categorical form of statement from &quot; If any S 

 is M it is P &quot; to &quot; All S M is P &quot;. If, however, we interpret the 

 universal categorical as not implying the existence of its subject, 

 then the universal forms &quot; If Any S is M it is P&quot; and &quot; All S M 

 is /&quot; would be mutually interchangeable. 2 



Particular conditionals for the most part merely assert the 

 results of concrete experience. Hence these may be taken as 

 implying the existence of their antecedents, and as, therefore, 

 mutually interchangeable with particular categoricals. The pro 

 position : &quot; Sometimes if heavy rains are followed by high winds 

 forests are seriously damaged may be expressed &quot; High winds 

 following heavy rains sometimes cause serious damage to forests &quot;. 



Dr. Venn maintains 3 that although the categorical form sometimes 

 prevails where the subject is doubtful, and the hypothetical where the ante 

 cedent is certain, nevertheless the &quot; original and fundamental distinction 

 between these forms (&quot; X is Y&quot; and &quot; if X then F&quot;) is &quot; that the presence 

 or existence of the subject is taken for granted, whilst that of the antecedent 

 is recognized as being doubtful &quot;. 



But even though all conditional judgments involve some element of doubt, 

 at least about the identification of the case, with the class, in the sense explained 

 by Dr. Venn, still it cannot be denied that some universal conditionals 

 like some universal categoricals imply the occurrence rather than the non- 

 occurrence of their antecedents : those, namely, that are based upon concrete 



1 ibid., p. 263. 



3 The transference of a judgment from any one to any other of the classes based 

 on RELATION (88) Categorical, Hypothetical, Disjunctive, etc. is called Change 

 of Relation, or Transversion. 



3 ibid., pp. 257 sqq. 



