FUNCTIONS AND VALUE OF THE SYLLOGISM. 219 



full extent, the whole of what our evidence must prove if it 

 proves anything. 



This throwing of the whole hody of possible inferences 

 from a given set of particulars, into one general expression, 

 operates as a security for their being just inferences, in more 

 ways than one. First, the general principle presents a larger 

 object to the imagination than any of the singular proposi 

 tions which it contains. A process of thought which leads to 

 a comprehensive generality, is felt as of greater importance 

 than one which terminates in an insulated fact ; and the mind 

 is, even unconsciously, led to bestow greater attention upon 

 the process, and to weigh more carefully the sufficiency of the 

 experience appealed to, for supporting the inference grounded 

 upon it. There is another, and a more important, advantage. 

 In reasoning from a course of individual observations to some 

 new and unobserved case, which we are but imperfectly 

 acquainted with (or we should not be inquiring into it), and 

 in which, since we are inquiring into it, we probably feel a 

 peculiar interest ; there is very little to prevent us from giving 

 way to negligence, or to any bias which may affect our wishes 

 or our imagination, and, under that influence, accepting in- 

 sufficienf evidence as sufficient. But if, instead of concluding 

 straight to the particular case, we place before ourselves an 

 entire class of facts the whole contents of a general proposi 

 tion, every tittle of which is legitimately inferrible from our 

 premises, if that one particular conclusion is so ; there is then 

 a considerable likelihood that if the premises are insufficient, 

 and the general inference, therefore, groundless, it will com 

 prise within it some fact or facts the reverse of which we 

 already know to be true ; and we shall thus discover the error 

 in our generalization by a reductio ad impossibile. 



Thus if, during the reign of Marcus Aurelius, a subject of 

 the Roman empire, under the bias naturally given to the 

 imagination and expectations by the lives and characters of 

 the Antonines, had been disposed to expect that Commodus 

 would be a just ruler ; supposing him to stop there, he might 

 only have been undeceived by sad experience. But if he 



