EAST AND WEST 159 



discovered them, but we are anxious to find out how much we 

 owe to each of them, in what kind of environment knowledge 

 developed, and which devious ways the human spirit followed 

 throughout the ages. After the sixteenth century, when science 

 was finally disentangled from theology, the distinction between 

 Jewish, Christian, and Muslim science ceased to be justified, 

 but it keeps its historical value. In spite of his deep Jewishness and 

 of his abundant use of Jewish sources, we do not count Spinoza 

 any more as a Jewish philosopher in the same sense that we count 

 Maimonides or Levi ben Gershon; he is one of the founders of 

 modern philosophy, one of the noblest representatives of the 

 human mind, not eastern or western, but the two unified. 



Perhaps the main, as well as the least obvious, achievement of 

 the Middle Ages, was the creation of the experimental spirit, or 

 more exactly, its slow incubation. This was primarily due to 

 Muslims down to the end of the twelfth century, then to Chris- 

 tians. Thus in this essential respect, East and West cooperated 

 like brothers. However much one may admire Greek science, one 

 must recognize that it was sadly deficient with regard to this 

 (the experimental) point of view which turned out to be the 

 fundamental point of view of modern science. Though their 

 great physicians instinctively followed experimental methods, 

 these methods were never properly appreciated by their philos- 

 ophers or by the students of nature. A history of Greek experi- 

 mental science, outside of medicine, would be exceedingly short. 

 Under the influence of Arabic alchemists and opticians, and later 

 of Christian mechanicians and physicists, the experimental spirit 

 grew very slowly. For centuries it remained very weak, com- 

 parable to a delicate little plant, always in danger of being ruth- 

 lessly trampled down by dogmatic theologians and conceited 

 philosophers. The tremendous awakening due to the western 

 re-discovery of printing and to the exploration of the new world, 

 accelerated its development. By the beginning of the sixteenth 

 century it was already lifting its head up, and we may consider 



