150 The Revolutions of Civilizaimi. [April 28, 



A similar period of about 1500 years has occurred in India and 

 Mexico. The Etruscan Sages assigned 1100 years as the period of a 

 race, after which it must be succeeded by another. 



The various activities of man are related in the same order in 

 each successive period. This can be best traced in the MediiBval and 

 Classical periods, where the stages of sculpture, painting, literature, 

 music, mechanics, science, and wealth spread over some seven cen- 

 turies. These stages were nearer together in earlier ages, but the 

 order was always the same so far as can be traced. 



The starting point of each civilization — as of each generation — is 

 a mixture of blood. Without a fusion of race no fresh start can be 

 made. About six or eight centuries is needed for the rise to the 

 sculpture stage. The growth of civilization largely consists in a 

 lengthening out of the subsequent stages of activity, and diminution 

 of the stagnant period before a new mixture is started. The period 

 seems to belong to the people and not to the country, and is kept 

 by the people when they go to a land of a different phase. 



Though, no doubt, climatic periods have a precipitating effect in 

 throwing one people on to another, yet the general regularity of 

 interval of the stages of growth of civilization point to a racial 

 determinant. This may be the time required to promote the maxi- 

 mum mixture of different strains in two races which are in contact. 



We have now co-ordinated the facts of civiHzations, and see how 

 general is the type of development and the period. We can take an 

 intelligent view of what we know of mankind as a systematic whole, 

 following a regular series of seasonal changes age after age. The 

 details, and the illustrations of the rise and fall of each stage, are 

 published in a small volume (Harpers) under the title of this lecture, 

 being too voluminous for these Proceedings. 



