8 EVOLUTION AND GENETICS 



In spite of the inaccuracies of some of these views and certain 

 other erroneous opinions which he held, Aristotle's work eclipses 

 that of all other ancient scientists in this field and he was not sur- 

 passed until the beginning of modern scientific methods several 

 centuries later. 



Through the Dark Ages. For years after Aristotle's life the 

 contributions which can be said to have any bearing on the prob- 

 lems of organic development and the origin of life have no more 

 than minor biological significance. Pliny (27-79 a.d.) and Galen 

 (131-200 A.D.) are the most conspicuous figures of the few suc- 

 ceeding centuries; the former did little or nothing of sound scientific 

 value, but Galen was a remarkable observer, clear thinker and 

 excellent writer. He was the foremost anatomist of antiquity. 

 Finally the influence of the early Christian church, favoring "tra- 

 ditional knowledge and the special-creation idea in its most literal 

 form", so hindered independent thought that not until the six- 

 teenth century was progress again resumed. It is gratifying to 

 note that even during this dark period three theologians, Gregory 

 of Nyssa (331-396 a.d.), Augustine (353-430 a.d.), and Thomas 

 Aquinas (1225-1274 a.d.) expressed belief in the symbohc nature 

 of the Biblical story of the creation. 



Development of Scientific Methods. An inevitable step in 

 the development of true natural science was the departure from 

 unsupported or poorly supported philosophical reasoning and 

 reference to authority, which took place soon after the renewal of 

 scientific thought. During the sixteenth century great strides 

 were made in the development of modern scientific methods, and 

 since then there has been no interruption of progress. Vesalius 

 (1514-1564) in anatomy and Harvey (1578-1667) in physiology 

 are outstanding figures in this period. Each applied to his work 

 sound principles of observation and experiment, and each is known 

 for the accurate contril)utions to science which resulted from these 

 methods. A little later the microscope was introduced, and in- 

 vestigation of fields hitherto ])arred from human vision began. 

 Hooke (1635-1703), Malpighi (1628-1694), Swammerdam (1737- 

 1680) and Leeuwenhoek (1632-1723) were among the pioneers in 

 microscopic work, which has been destined to play such a large 

 part in the biological sciences. 



Philosophy was not neglected during this period. The names 

 of Bacon (1561 1626) and Kant (1724-1804) especially are cited in 



