205 



POPULAR SCIENCE MONTHLY. 



CORRESPONDENCE. 



COMPARATIVE LONGEVITY AND 

 GREATNESS. 



Whether or not great men are fa- 

 vored by an increase of years above 

 those allotted to more ordinary mor- 

 tals has long been a question of inter- 

 est, and has acquired a special impor- 

 tance in connection with the study of 

 the natural history of men of genius, 

 and the discussions of the possible re- 

 lation of greatness to degeneracy and 

 to insanity. Questions of this type can 

 only be decided on the basis of extensive 

 and carefully collected data, which un- 

 fortunately it is difficult and at times 

 impossible to collect or to find. It is 

 therefore natural that such evidence as 

 seems to exist and to carry with it some 

 degree of logical force should be brought 

 forward in proof of a claim which on 

 general principles is both pleasing and 

 plausible. Of this type is the problem 

 of the relation between longevity and 

 greatness, and of this type is the evi- 

 dence now and then brought forward 

 to substantiate the belief that great 

 men are, as regards longevity, an un- 

 usually favored class. 



The most recent presentation of the 

 topic (by Mr. Thayer in the Forum, Feb- 

 ruary, 1900) collects a list of some five 

 hundred prominent men and women of 

 the nineteenth century and finds that 

 these persons lived on an average 

 sixty-eight years and eight months; 

 that is, nearly thirty years longer 

 than the population as a whole. And 

 on the basis of this conclusion the 

 writer combats the notion that nine- 

 teenth-century men of genius or of 

 eminence exhibit signs of degeneracy, 

 because longevity and the ability to do 

 sustained work for a large number of 

 years is in itself a sign of unusual vital- 

 ity and vigor. As these conclusions are 

 apt to be extensively quoted, and as 



they seem to me founded upon a serious 

 fallacy, I shall attempt to present as 

 simply as possible the nature of the 

 desired evidence which alone could 

 prove that great men are longer lived 

 than others, and to show that the evi- 

 dence thus far presented is inadequate 

 to support the conclusion which has 

 been drawn. Mr. Thayer is not the 

 first one to present the average age at 

 death of a number of eminent -persons 

 as evidence of unusual longevity. In 

 an article which was reprinted in the 

 Popular Science Monthly for May, 1884, 

 the average age at death of 1,741 

 astronomers was given, and found to be 

 sixty-four years and three months; and 

 on the basis of this fact the author 

 claimed that astronomers enjoyed un- 

 usual longevity. In a brief contribu- 

 tion published in Science, October 1, 

 1886 (and republished in Nature, No- 

 vember 4, 1886), I called attention to 

 the fallacy inherent in such conclusions, 

 and also presented some new contribu- 

 tions to the question of the longevity of 

 great men. The materials of that 

 article I shall utilize in the present dis- 

 cussion. 



To reach the kernel of the matter at 

 once, the reader must note that the 

 fallacy consists in neglecting to con- 

 sider that in dealing with astronomers 

 or with great men, or with persons of 

 eminence of the nineteenth century, one 

 is dealing with a group which is already 

 carefully selected,- and the selection of 

 which inevitably involves the attain- 

 ment of a certain age. The result is 

 that we are not dealing with average 

 persons as regards longevity, but with 

 persons who in the very nature of 

 things have already reached a certain 

 period of maturity. No one can be- 

 come a poet, or a novelist, or a painter. 

 or a philosopher, or a commander or a 



