6^6 THE POPULAR SCIENCE MONTHLY. 



this unobtrusive but speedy diffusion of knowledge, there came, along 

 with a growing consciousness of the still-remaining deficiency, the 

 system of State-subsidies ; which, beginning with 20,000, grew, in 

 less than thirty years, to more than a million. Yet now, after this 

 vast progress at an ever-increasing rate, there has come the outcry 

 that the nation is perishing for lack of knowledge. Any one not 

 knowing the past, and judging from the statements of those who have 

 been urging on educational organizations, would suppose that strenuous 

 efforts are imperative to save the people from some gulf of demorali- 

 zation and crime, into which ignorance is sweeping them. 



How testimonies respecting objective facts are thus perverted by 

 the subjective states of the witnesses, and how we have to be ever on 

 our guard against this cause of vitiation in sociological evidence, may 

 indeed be inferred from, the illusions that daily mislead men in their 

 comparisons of past with present. Returning after many years to the 

 place of his boyhood, and finding how insignificant are the buildings 

 he remembered as so imposing, every one discovers that in this case it 

 was not that the past was so grand, but that his impressibility was so 

 great and his power of criticism so small. He does not perceive, how- 

 ever, that the like holds generally ; and that the apparent decline in 

 various things is really due to the widening of his experiences and the 

 growth of a judgment no longer so easily satisfied. Hence the mass of 

 witnesses may be under the impression that there is going on a change 

 just the reverse of that which is really going on ; as we see, for ex- 

 ample, in the notion current in every age, that the size and strength 

 of the race have been decreasing, when, as proved by bones, by mum- 

 mies, and by armor, and by the experiences of travellers in contact 

 with aboriginal races, they have been on the average increasing. 



Most testimony, then, on which we have to form ideas of sociologi- 

 cal states, past and present, has to be discounted to meet this cause of 

 error ; and the rate of discount has to be varied according to the 

 epoch, and the subject, and the witness. 



Beyond this vitiation of sociological evidence by general subjective 

 states of the witnesses, there are vitiations due to more special sub- 

 jective states. Of these, the first to be noted are those which foregone 

 conclusions produce. 



Extreme cases are furnished by fanatical agitators, such as mem- 

 bers of the Anti-Tobacco Society, in the account of whose late meeting 

 we read that " statistics of heart-disease, of insanity, of paralysis, and 

 the diminished bulk and stature of the population of both sexes proved, 

 according to the report, that these diseases were attributable to the 

 use of tobacco." But without making much of instances so glaring as 

 this, we may find abundant proof that evidence is in most cases uncon- 

 sciously distorted by the pet theories of those who give it. 



Early in the history of our sanitary legislation, a leading officer of 



