CLASSICAL ANTIQUITY, MIDDLE AGES 8l 



released. No small cause of the mistrust he inspired was his interest in phys- 

 ical and chemical experiments, which resulted in his being suspected of 

 witchcraft and necromancy. Although he appears to have been a clever 

 experimentalist with a wide general knowledge, there is nevertheless no 

 record of any epoch-making scientific discovery that can be attributed to 

 him. His greatness lies in his general scientific ideas. He set himself up in 

 determined opposition to the subtle mode of thinking of the schoolmen and 

 urged that science should rather be based upon experience gained through 

 observing natural phenonema — that is to say, upon a method harmonizing 

 with that which has been adopted in natural-scientific research in more 

 recent times. 



Appearance of neiv ideas 

 This intellectual emancipation from the hidebound teachings of authority 

 was inspired, however, less by the theoretical contributions of Roger Bacon 

 and any of his successors than by the increasing knowledge of nature itself 

 resulting from the discovery and exploration of new countries. The crusades 

 had already made some contribution towards this expansion, but still greater 

 was the influence of the knowledge of far-distant lands acquired through 

 the journeys into the interior of Asia undertaken by Marco Polo and several 

 of his contemporaries, and further through the widely extended voyages of 

 the Portuguese in the fifteenth century, and finally through the discovery 

 of America. As a result of all these geographical discoveries biology also ac- 

 quired a mass of fresh material, which it was impossible to deal with merely 

 by studying Aristotle; it forced research rather to seek its own paths and 

 research-workers to rely more upon themselves. Biology was thus compelled 

 to abandon the purely literary method of compilation and classification, 

 which had been the most characteristic feature of medixval science, and 

 instead had to rely for its progress upon working out its own observations 

 and developing the results thereof. But before it could do this, biology had 

 to free itself from the restrictions which the ecclesiastical authority of the 

 Middle Ages had laid upon man's intellectual activities in general, and it 

 thus came to take part in the great work of intellectual liberation whose 

 various phases in history are generally summarized under the name of the 

 Renaissance. The progress thus achieved in the knowledge of living nature 

 will be dealt with in the next chapters. 



