366 POPULAR SCIENCE MONTHLY. 



know that there are to the best of our present knowledge twelve men 

 more eminent than Homer and fifty-six men more eminent than 

 Virgil. Further by reckoning the probable errors it is found that the 

 chances are even that Homer's place on the list is between 10 and 26 

 and Virgil's between 42 and 98. 



But while our general knowledge apart from any such list as this 

 may suffice to compare Homer with Virgil as accurately as is needful, 

 this does not hold for men whose work is not readily comparable. Is 

 Raphael, Descartes or Columbus the more eminent? As a matter of 

 fact they stand respectively 2 2d, 23d and 24th on the list, and are 

 equally eminent. I do not see how this result could have been reached 

 from any general knowledge we may have of the work and fame of these 

 men. Or again, Newton follows Homer and Hume follows Virgil on 

 the list, consequently Newton is as much more eminent than Hume as 

 Homer is than Virgil. 



Things can be arranged in order more easily than they can be 

 measured. We know that one sound is louder than another, though 

 we may be unable to say whether it is more or less than twice as loud. 

 We can arrange without much difficulty the examination papers of our 

 students in the order of excellence, though unable to decide that one 

 paper is twice as good as another. But the theory of probability makes 

 even the measurement of the eminence of great men possible. 



If all the men of the races and ages with which we are concerned 

 were arranged in order, we might divide them into quarters. Sup- 

 posing there to be one hundred million individuals in all from whom 

 these men might have arisen, taking the adult male population of the 

 countries and periods producing nearly all of them, we should have at 

 the end the 25 million least deserving of credit, including the defective 

 and delinquent classes. Then we should have two groups each con- 

 taining 25 million, one falling below and one rising above the average. 

 These are the ordinary men who depart from the median by an amount 

 less than the probable error. Then at the upper end we have the group 

 of 25 million individuals who through some special trait or through 

 a combination of traits rise above the others. At the extreme end of 

 this group are the thousand preeminent men of our list. 



What a man is and does is the result of innumerable influences, 

 chiefly small and independent, some pulling him down and some lifting 

 him up. In so far as this is the case, the men will be grouped together 

 and depart from each other in a certain definite fashion. The matter 

 can most readily be illustrated by taking a single trait such as height. 

 If these men were placed in a row arranged according to height, the 

 tops of their heads would form a curve of which an exaggerated form is 

 given. In a general way the middle man would be of the average height, 



