Sd8 



SCIENCE. 



[N. S. Vol. XX. No. 508. 



■ceean. I think it is thus in the develop- 

 jnent of humanity. Long ages may pass 

 during which a race, to all external observa- 

 tions,, appears to be making no real prog- 

 ress. Additions may be made to learning, 

 and the records of history may constantly 

 grow, but there is nothing in its sphere of 

 thought or in the features of its life that 

 can be called radically new. Yet, nature 

 may have been all along slowly working in 

 a way which evades our scrutiny until the 

 result of her operations suddenly appears 

 in a new and revolutionary movement, car- 

 rying the race to a higher plane of civiliza- 

 tion. 



It is not difficult to point out such epochs 

 in human progress. The greatest of all, 

 because it was the first, is one of which we 

 find no record either in written or geological 

 history. It was the epoch when our pro- 

 genitors first took conscious thought of the 

 morrow, first used the crude weapons which 

 nature had placed within their reach to 

 kill their prey, first built a fire to warm 

 their bodies and cook their food. I love to 

 fancy that there was some one first man, 

 the Adam of evolution, who did all this, 

 and who used the power thus acquired to 

 show his fellows how they might profit by 

 his example. Wlien the members of the 

 tribe or community which he gathered 

 around him began to conceive of life as a 

 whole— to include yesterday, to-day and to- 

 morrow in the same mental grasp— to think 

 how they might apply the gifts of nature 

 to their own uses— a movement was begun 

 which should ultimately lead to civilization. 

 Many, indeed, must have been the ages 

 required for the development of this rudest 

 primitive community into the civilization 

 revealed to us by the most ancient tablets 

 of Egypt and Assyria. After spoken lan- 

 guage was developed, and after the rude 

 ■ representation of ideas by visible marks 

 drawn to resemble them had long been 

 practi'^ed, some real Cadmus must have in- 



vented an alphabet. When the use of a 

 written language was thus introduced, the 

 word of command ceased to be confined to 

 the range of the human voice, and it became 

 possible for master minds to extend their 

 influence as far as a written message could 

 be carried. Then were communities gath- 

 ered into provinces, provinces into king- 

 doms, and kingdoms into the great empires 

 of antiquity. Then arose a stage of civil- 

 ization which Ave find pictured in the most 

 ancient records— a stage in which men were 

 governed by laws that were perhaps as 

 wisely adapted to their conditions as our 

 laws are to ours — in which the phenomena 

 of nature were rudely observed, and stri- 

 king occurrences in the earth or in the 

 heavens recorded in the annals of the 

 nation. 



Vast was the progress of knowledge dur- 

 ing the interval between these empires and 

 the century preceding that in which modern 

 science began. Yet, if I am right in ma- 

 king a distinction between the slow and 

 regular steps of progress, each growing 

 naturally out of that which preceded it, 

 and the entrance of the mind at some fairly 

 definite epoch into an entirely new sphere 

 of activity, it woidd appear that there was 

 only one such epoch during the entire in- 

 terval. This was when abstract geometrical 

 reasoning commenced, and astronomical ob- 

 servations aiming at precision were re- 

 corded, compared and discussed. Closely 

 associated with it must have been the con- 

 struction of the forms of logic. The rad- 

 ical difference between the demonstration 

 of a theorem of geometry and the reasoning 

 of every-day life, which the masses of men 

 must have used from the beginning, and 

 which few even to-day ever get beyond, 

 is so evident at a glance that I need not 

 dwell upon it. The principal feature of 

 this advance is that by one of those 

 antinomies of the human intellect of which 

 examples are not wanting even in our own 



