THE EMERGENCE OF MODERN SCIENCE 83 



primarily upon the development of experimental and 

 analytical methods. While the spirit and appreciation of 

 science appear in da Vinci, the modern intensive attack 

 appears first in the investigations of Galileo (1564-1642). 

 Building upon the work of Copernicus, Galileo continued the 

 advance in astronomy despite theological opposition. By 

 the year 1700, Descartes (1596-1650) and Pascal (1623- 

 1662), by establishing the theory of probability had elimi- 

 nated evil spirits from many hitherto inexplicable phenom- 

 ena on the earth, while Kepler (1571-1630) and Newton 

 (1642-1727) had enthroned natural law in the heavens. 



Geographical and astronomical science were established by 

 the voyages of discovery, and by the scientific work of 

 Copernicus and Galileo. Chemistry, which had existed as 

 alchemy since the early Christian Era and which had been 

 defined during the eleventh century as "the preparation of 

 silver and gold," received an impetus through the chemical 

 medicine of Paracelsus (1493-1541); while the foundation 

 of modern chemistry was laid by Boyle (1627-1691) who 

 defined chemistry as "the composition of substances," and 

 emphasized the methods of experimentation and inductive 

 reasoning. Boyle defined the elements as substances in- 

 capable of decomposition, and the compounds as substances 

 composed of elements, but the development of this general- 

 ization was subsequently held in abeyance by the promulga- 

 tion of the erroneous Phlogiston-Theory. s 



Within the field of physical and mathematical sciences, 

 Galileo had established the science of dynamics by his ex- 

 periments with falling bodies. His laws of motion had made 

 possible the explanation of the continuous movement of the 

 planets, but their orbital movement remained unexplained. 

 Newton applied to the heavens the simple, though even now 

 inexplicable, phenomenon of gravitation; and calculated the 

 sweep of the planets in the same terms as the fall of a stone. 

 His emotional excitement during the conclusion of his cal- 

 8 See: note, p. 97 of the present volume. 



