NA TURE 



\_Ncv. 4, i8S6 



" Molecular Physics and Sound," and " The First Book 

 of Knowledge." 



He was elected a Fellow of the Royal Society of Edin- 

 burgh in 1S59, and a Fellow of the Royal Society of 

 London in 1S73. G. C. F. 



THE LONGEVITY OF GREAT MEN' 



"T^HE conclusion that the intellectual giants of the race 

 ■'■ are favoured by an abundance of years on the scene of 

 their heroic activity, and are thus further differentiated 

 from their more common fellow-men, seems natural, and 

 has been accepted upon evidence which, in a less pleasing 

 conclusion, would be considered ridiculously insufficient, 

 and even false. The usual method of attempting to 

 answer the question whether great men are longer-lived 

 than others, is to prepare a list of the ages, at death, of a 

 number of eminent men, take the average age, and com- 

 pare it with a similar average of a number of ordinary 

 men, or even with the average lifetime of the race, and in 

 this way to make the results speak decidedly in favour of 

 the superior longevity of great men. All that such a 

 method can prove (and this it does prove) is that it takes 

 long to become great. It neglects to consider that a 

 select class of men is dealt with, and that, to be even 

 potentially included in this class, one must have lived a 

 certain number of years. 



For example : in an article translated in the Popular 

 Scictice Monthly for May 1S84, it is argued that astro- 

 nomers are a long-lived race because the average life- 

 period of 1 741 astronomers is 64 years and 3 months. An 

 average human life is only 33 years ; but as one cannot 

 be an astronomer before adult life, the author takes the 

 expectation of life at iS years, which is 61 years, and thus 

 makes an excess of over 3 years in favour of astronomers. 

 He also divides his astronomers into four degrees of 

 eminence, and finds that those of the first rank live longer 

 than those of the second, and they in turn longer than 

 those of the third, and so on, thus implying that the best 

 astronomers are most favoured with years. The true 

 conclusion is, that it takes longer to become a first- 

 rank astronomer than it does to become a less eminent 

 one.'2 



If great men were great from their infancy, and we had 

 the means of ascertaining this fact, the method would be 

 correct. But, as it is, we must define in some way or 

 other what we mean by greatness, and then fix the average 

 age at which it becomes possible to distinguish an amount 

 of talent sufficient to enable its possessor to be enrolled in 

 the ranks of the great as already defined. What is known 

 as the " expectation of life " at any number of years tells 

 the most probable age at death of one who has attained 

 the years under consideration ; a comparison of this age 

 with the age at death of great men will decide whether 

 they are longer lived or not. 



The attempt was made to select about 280 to 300 of the 

 greatest men that ever lived.'' Throwing out about 30 of 

 the doubtful names, there remain 250 men, about whom 

 the statement is hazarded that a list of the 250 greatest 

 men, prepared by another set of persons, will not mate- 



* From Science. 



^ Mr. Galtjn (" Hereditary Geniu'^," p. 34) has allowed himself to neglect 

 a similar cons deration. In giving the number of men in each class that the 

 population of the Un.ted Kingdom wculd have between certain ages, he gives 

 35 as the number of men of class G (a very high degree of eminence) between 

 the .iges 20 and 30, and only 21 such men between 40 and 50 years. But 

 this cannot be true, because only a very sma 1 proportion of men could 

 possibly attain the eminence requisite to be classed among the G's in 20 to 

 30 years, while almost all (of those who will attain it at all) will have attained 

 it before the end of their fiftieth year. And this consideration far outbalances 

 the e.xcess in abolute number of men between the former ages over those 

 between the latter. Similarly the falling-oflf in the number of men of classy, 

 i.e, idiots, from decade to decade, would be more rapid than inordinary 

 men,— a fact which the tables fail to show. 



^ The names were selected by three others and myself, while engaged in a 

 study of what might be called the natural history of great men. The pr:cess 

 of selection was most rigid and careful, by a system which it would take too 

 long to describe. 



rially differ from our list, as far as all the purposes for 

 which it is to be used are concerned. From this list I 

 have selected at random a set of men of whom it was 

 probably easy to fix the age at which they had done work 

 which would entitle them to a place on this list, or work 

 which almost inevitably led to such distinction : it is a 

 date about midway between the first important work and 

 the greatest work. The average of over 60 such ages is 

 37 years ; which means, that, on the average, a man 

 must be 37 years old in order to be a candidate for a place 

 on this list. The real question, then, is, How does the 

 longevity of this select class of 37-year-old men compare 

 with that of more ordinary individuals .^ The answer is 

 given by the expectation of life at 37 years, which is 29 

 years, making the average age at death 66 years. And 

 this is precisely the age at death of the-e 60 great men ; 

 showing, that, as a class (for these 60 may be considered 

 a fair sample), great men are not distinguished by their 

 longevity from other men. 



Further interesting conclusions can be drawn if we 

 divide the men into classes, according to real psycho- 

 logical and physiological differences in the ways of mani- 

 festation of the several kinds of genius. It is almost 

 surprising how well the ordinary trinity of faculties — 

 intellect, emotions, and will — accomplishes this purpose. 

 Greatness seems to appear either in a brilliant thought, 

 a deep feeling, or a powerful will. Under men of thought 

 would be included philosophers, scientists, historians, &c. ; 

 under men of feeling, poets, musicians, religionists, &q. ; 

 under men of action, rulers, commanders, statesmen, &c. 

 Before comparing the relative longevity of these three 

 classes of men, 1 assure myself that the period at which 

 greatness begins to be possible does not materially difter' 

 in the three classes, and, as was done in the former case, 

 I exclude all cases of unnatural death. I find that men 

 of thought live 69'5 years, or 3'5 years longer than ordi- 

 nary men ; while the lives of men of feeling are 3 years, 

 those of men of action 5 years, shorter than those of 

 average men, — a conclusion that agrees with the commonly 

 accepted view on the subject. If we subdivide these 

 three classes, we find, that, w-hile all classes of men of 

 thought live longer than ordinary men, the moralists live 

 longest, scientists coming next ; that among the men of 

 feeling the religionists alone live the full period of life, 

 while poets' lives are 5 years, and musicians' lives 8 

 years, too short ; that, of men of action, rulers and com- 

 manders both fail to complete the full term of life by 

 4 years. One sees from these statements (which, however, 

 in their detail at least, must be accepted with hesitation, 

 owing to the fewness of examples) that the kind of 

 psychical and physical activity pursued influences the 

 life-period ; that certain types of genius are apt to die 

 young, while others are particularly favoured with a full 

 allowance of years. 



The question of longevity becomes important when we 

 consider that through it the leaders of civilisation are 

 allowed to exercise their important function a few years 

 longer, thus enabling more great men to be alive at the 

 same time ; and that, by its tendency to be inherited by 

 the oftspring, the children of great men will begin life 

 with a better chance of teaching maturity, and, in turn, 

 of becoming important to the world, if, as we have reason 

 to believe it would, the genius of their ancestors has left its 

 traces m them. JOSEPH J.\STROW 



THE GEOLOGY OF THE LEBANON 



WE are indebted to Dr. Carl Diener, of the University 

 of Vienna, for an able monograph on the geolo- 

 gical and physical formation of the Lebanon and sur- 

 rounding districts, accompanied by maps, sections, and 



■ IVIr. Sully (Sitictcentk Century, June iS36) has sh^wn thai men of 

 feeling are more precocious than men of thought ; but the difference in the 

 age at which iheir first great work is done, though'in favour of men of 

 feeling, is very slight indeed. 



