544 THE POPULAR SCIENCE MONTHLY. 



mental images should sometimes closely resemble these portraits ex- 

 cept in one important respect ; namely, that the effect produced by the 

 huge bulk of ordinary facts is never in proportion to their numbers. 

 Consequently, we find that undue consideration is inevitably given 

 in generic images to all exceptional cases. When the exceptions in 

 excess are balanced by those in deficiency, the value of the average 

 will not be affected, and there is always a tendency toward that result. 

 The fault that remains wholly uncorrected is, that the great prevalence 

 of mediocre instances is overlooked, and the number and importance 

 of the deviations are largely over-estimated. The tendency of the 

 mind of the child and of the savage, and in all branches of knowledge 

 in their prescientific stage, is necessarily toward the marvelous and the 

 miraculous. 



The generic images that might arise in a mind superhumanly logi- 

 cal and active would be subject to no other error than this, but in the 

 human mind it is not so. Some of the images in every presumed ge- 

 neric group are sure to be aliens to the genus and to have become 

 associated to the rest by superficial and fallacious resemblances, such 

 as common minds are especially attentive to. Again, the number of 

 pictures that are blended together is sure to fall far short of the whole 

 store that would be available if the memory were immeasurably 

 stronger than it is, and more ready in its action. Knowing also as I 

 do, from considerable experience of composites, what monstrous and 

 abortive productions may result from ill-sorted combinations of por- 

 traits, and how much care in selection and nicety of adjustment is 

 required to produce the truest possible generic image, I cease to won- 

 der at the numerous shortcomings in our generalizations and at their 

 absurd and frequent fallacies. The human mind is a most imperfect 

 apparatus for the elaboration of true general ideas. Compared with 

 the mind of brutes, its powers are marvelous ; but for all that they 

 fall vastly short of perfection. The criterion of a perfect mind would 

 be the power of always creating vivid images of a truly generic kind, 

 deduced from the whole range of its past experiences. 



General impressions are the faint traces left by generic images, and 

 have all their defects, as well as others, due to their own want of defi- 

 nition. They are never to be trusted. Unfortunately, when general 

 impressions are of long standing they become fixed rules of life, and 

 assume a prescriptive right not to be questioned. Consequently, those 

 who are not accustomed to original inquiry entertain a hatred and 

 horror of statistics. They can not endure the notion of submitting 

 their sacred general impressions to cold-blooded verification. But it is 

 the triumph of scientific men to rise superior to such superstitions, to 

 devise tests by which the value of beliefs may be ascertained, and to 

 feel sufficiently masters of themselves to discard contemptuously what- 

 ever may be found untrue. Nineteenth Century. 



