342 FALLACIES. 



The former case, in so far as the act of induction from 

 insufficient evidence is concerned, does not fall under this 

 second class of Fallacies, but under the third, Fallacies of 

 Generalization. In every such case, however, there are two 

 defects or errors instead of one : there is the error of treating 

 the insufficient evidence as if it were sufficient, which is a 

 Fallacy of the third class ; and there is the insufficiency itself; 

 the not having better evidence ; which, when such evidence, 

 or in other words, when other instances, were to be had, is 

 Non-observation : and the erroneous inference, so far as it 

 is to be attributed to this cause, is a Fallacy of the second 

 class. 



It belongs not to our purpose to treat of non-observation 

 as arising from casual inattention, from general slovenliness of 

 mental habits, want of due practice in the use of the observing 

 faculties, or insufficient interest in the subject. The question 

 pertinent to logic is Granting the want of complete compe- 

 tency in the observer, on what points is that insufficiency on 

 his part likely to lead him wrong ? or rather, what sorts of 

 instances, or of circumstances in any given instance, are most 

 likely to escape the notice of observers generally ; of mankind 

 at large. 



3. First, then, it is evident that when the instances on 

 one side of a question are more likely to be remembered and 

 recorded than those on the other ; especially if there be any 

 strong motive to preserve the memory of the first, but not of 

 the latter ; these last are likely to be overlooked, and escape 

 the observation of the mass of mankind. This is the recog- 

 nised explanation of the credit given, in spite of reason and 

 evidence, to many classes of impostors : to quack doctors, and 

 fortune-tellers in all ages ; to the " cunning man " of modern 

 times and the oracles of old. Few have considered the extent 

 to which this fallacy operates in practice, even in the teeth of 

 the most palpable negative evidence. A striking example of 

 it is the faith which the uneducated portion of the agricultural 

 classes, in this and other countries, continue to repose in 

 the prophecies as to weather supplied by almanac makers : 



