248 EPOCHS IN THE HISTORY OF THE CONTEMPLATION OF 



natural sciences, to their mathematical foundation, and to 

 the intentional production of phenomena in the way of 

 experiment, Albert von Bollstadt or Albertus Magnus, the 

 cotemporary of Eoger Bacon, holds the foremost place in 

 the middle ages. These two men occupy between them 

 almost the entire thirteenth century; but to B/oger Bacon 

 belongs the praise, that the influence exerted by him on the 

 form and treatment of the study of nature was more bene- 

 ficial, and more permanent in its operation, than the several 

 discoveries wliich have been with more or less correctness 

 ascribed to him. Awakened himself to independent thought, 

 he condemned strongly the blind faith in the authorities of 

 the schools ; yet far from being indifferent to the investiga- 

 tion of Grecian antiquity, he at the same time appreciated 

 and valued a thorough study of that language, ( 382 ) the ap- 

 plication of mathematics, and the " Scientia experimentalis/' 

 to wliich last he devoted a particular section of the Opus 

 Majus. ( 38S ) Protected and favoured by one pope 

 (Clement IY.), and accused of magic and imprisoned by 

 two others (Nicholas III. and IY.), he experienced the 

 alternations of fortune to which in all ages great minds 

 have frequently been subject. He was acquainted with 

 Ptolemy's Optics, ( 384 ) and with the Almagest. As, like 

 the Arabians, he always calls Hipparchus Abraxis, we may 

 infer that he too only made use of a Latin translation 

 derived from the Arabic. Next to his chemical experiments 

 on combustible explosive mixtures, his theoretico-optical 

 works on perspective, and on the position of the focus in 

 concave mirrors, are the most important. His Opus Majus, 

 which is full of thought, contains proposals and plans of 

 possible execution, but no clear traces of success in optical 



