HISTORICAL ACCOUNT OF EVOLUTION THEORY ' 15 



Augustine (353-430 a.d.) conceived the idea, now so generally 

 adopted by theologians, that the biblical account of creation is alle- 

 gorical. "In explaining the passage 'In the beginning God created 

 heaven and the earth,' he says: 



"In the beginning God made the heaven and the earth, as if this 

 were the seed of the heaven and the earth, although as yet all the 

 matter of heaven and of earth was in confusion, but because it was 

 certain that from this the heaven and the earth would be, therefore 

 the material itself is called by that name. " 



Thomas Aquinas (1225-74), who wrote much later and was one of 

 the leading church authorities, satisfied himself with merely expound- 

 ing Augustine: "As to the production of plants, Augustine holds a 

 different view, .... for some say that on the third day plants were 

 actually produced, each in its kind — a view favoured by the superficial 

 reading of Scripture. But Augustine says that the earth is then said 

 to have brought forth grass and trees Qausaliter; that is, it then 

 received the power to produce them. For in those first days .... 

 God made creation primarily or causaliter, and then rested from His 

 work." 



THE REVIVAL OF SCIENCE 



During the long centuries until the awakening of science in the 

 Middle Ages the evolution idea smouldered along in the minds of a 

 few thinkers, but it was only when a few daring spirits broke the 

 trammels of scholasticism and began once more to give free rein to 

 observation and speculation that the idea once more burst into flame 

 and began its second great period of advance. 



A small group of natural philosophers, scarcely more scientific 

 in their methods than the Greeks, were the first to revive interest in 

 the evolution idea. Of these the names of Bacon, Descartes, Leib- 

 nitz, and Kant are the most famous. 



Francis Bacon (1561-1626) did much to revive the vogue of Aris- 

 totelian ideas. He also added some new ideas: (i) that the muta- 

 bility of species was the result of the accumulation of variations; (2) 

 that variations of an extreme kind, equivalent to "mutations," some- 

 times occur; (3) that new species might arise by a degenerative 

 process from old species. 



Emanuel Kant (17 24-1 804) was purely a philosopher, not an 

 observing naturalist, but he profited by the writings of the contem- 

 porary naturalists, especially those of Buff on and Maupertius. His 



