THE EVOLUTION OP THE IDEA OP EVOLUTION 5 



of these leaders of the " Ionic school," to which all the 

 preceding belonged. 



But the best and most finished account of the theory is 

 found in the work of the Latin poet, Lucretius, De rerum 

 natura (" On the nature of things "). Just as the curtain 

 was falling on the brilliant episode of Greek civilisation, 

 their culture was transferred to Rome, in the century 

 before the birth of Christ. The Romans were great 

 administrators and lawyers, and we are not surprised 

 that in their hands science and philosophy developed no 

 further; but it is in the poetry of Lucretius, a disciple of 

 Epicurus, that we find the idea of evolution in the 

 highest form it attained in the Greek mind. The infinite 

 number of atoms is now ruled by law, instead of tossing 

 aimlessly in the void. They group themselves according 

 to their affinities, and form large and complex bodies. 

 "The earth, the sun, heaven, and the race of living 

 things," are slowly formed out of their orderly combina- 

 tion. First plants and then animals arose out of the 

 earth, "the mother of all things," under the influence of 

 rain and heat; many of the living forms that arose, 

 though they were not the grotesque monsters of 

 Empedocles, were unfitted for life on earth and perished. 

 Men were evolved from non-human animals. They were 

 at first all savages, without speech or social order; and 

 in the development of civilisation they passed from an 

 age of stone weapons to the use of metals, first copper 

 and then iron. 



These fortunate conjectures are, we must always 

 remember, mixed up with a larger proportion of crude 

 speculation. With the exception of Aristotle, the Greeks 

 slighted exact observation and were ignorant of experi- 

 ment ; they trusted unduly to philosophical speculation 

 about things. Yet there can be little doubt that if their 

 culture had been evenly developed we should be much 



