CONDITIONAL JUDGMENTS AND PROPOSITIONS 279 



The most common and dangerous fallacy in eductions from 

 hypotheticals is that which is analogous to the simple conversion 

 of a categorical A proposition, viz. the inferring of &quot; If C then 

 A &quot; from &quot; If A then C&quot;. Similar to this is the fallacy of inferring 

 a simple contrapositive from E, i.e. of inferring &quot; If not C then 

 A &quot; from &quot;If A then not C&quot;. Finally, the inferring of a simple 

 inverse from either A or E is a fallacy not always avoided. &quot;If 

 A then C&quot; does not yield &quot; If not A then not C&quot; but only &quot;If not A 

 then perhaps not &quot; ; nor does &quot; If A then not C&quot; yield &quot;If not 

 A then C,&quot; but only &quot; If not A then perhaps C&quot;. 



KEYNES, Formal Logic, part ii., chap. ix. JOSEPH, Logic, pp. 163-66. 

 WELTON, Logic, i., pp. 181-86, 244, 271-73. VENN, Empirical Logic^ 

 248-64. 



