332 THE CHANGING GENERATIONS 



nearly all primitive peoples. However, evolution has left so many clues 

 and traces that we can scarcely suppose that they passed altogether 

 unnoticed. It is probable that an occasional exceptionally acute observer 

 and profound thinker must have caught glimpses of the truth even before 

 the dawn of history. 



However this may be, the oldest records of evolutionary speculations 

 that have come down to us are the ideas of certain Greek philosophers 

 of the sixth and fifth centuries b.c. These men had little biological knowl- 

 edge to guide them and were groping in the dark. Their ideas were ex- 

 tremely vague, and, although interesting, were not really anticipatory 

 of modern evolutionary doctrine as is sometimes claimed. During this 

 early period of Greek philosophy a materialistic attitude prevailed, and 

 purely natural causes were sought for all phenomena — a viewpoint not 

 far removed from that of modern science. Later, under the influence of 

 Socrates and Plato, a reaction took place. Material phenomena came 

 to be regarded as the mere outward expression of abstract ideas, which 

 were the true realities. Aristotle (350 b.c), the greatest of the Greek 

 natural philosophers, was the prime exponent of this view. Scientist 

 as well as philosopher, Aristotle knew more about animals and plants 

 than any man of his time or for generations to follow. He wrote a de- 

 tailed treatise on the animals known to him, including many accurate 

 observations on their anatomical structure. Through his wide acquaint- 

 ance with organisms and his use of the comparative method of study, he 

 was aware of the fact that they form graded series from lower to higher 

 types of organization, and he drew from this the correct inference that 

 they have evolved. He looked upon their evolution from lower to higher 

 grades, however, as a striving toward the expression of an ideal " arche- 

 type" established by a supreme intellect. 



The doctrine of special creation. After this early flowering of science 

 in Greece more than fifteen centuries elapsed before progress in biology 

 was resumed. This long interval saw the rise and fall of Rome, with its 

 essentially utilitarian philosophy, the barbarian conquests, and the 

 confusion of the Middle Ages. During this time paganism was supplanted 

 by Christianity throughout nearly the whole of Europe, and the church 

 grew immensely in authority. Religion, commerce, and war were dominant 

 in men's thoughts, leaving scant room for science. 



The crusades during the eleventh to the thirteenth centuries brought 

 the Western peoples into contact with the Arabs, among whom such 

 sciences as mathematics, astronomy, and medicine had been carried to a 

 rather high development. This may have had something to do with the 

 intellectual revival in Europe that began in the eleventh century and 

 culminated in the Renaissance during the fifteenth and sixteenth cen- 

 turies. Now that men's interest and intellectual curiosity began once 



