84 GREAT MEN OF SCIENCE 



was brought forward and supported by Newton in the 

 work Philosophiae Naturalis Principia Mathematica ('The 

 Mathematical Principles of Natural Knowledge' would be 

 a suitable translation). At the same time he points out the 

 way to all future investigation, and indeed, as regards 

 mechanics -the phenomena of motion of massive objects- he 

 even completes the investigation in all fundamental respects. 

 If we open the book in order to examine it in detail, we are 

 astonished, quite apart from the main discovery, by every 

 part of it, and overwhelmed with admiration for the greatness, 

 the extent, the power, as well as the fineness of structure, of 

 what he erects upon the foundations given by Pythagoras, 

 Archimedes, Leonardo, Stevin, and in particular Galileo 

 and Huygens, using the material afforded by Copernicus, 

 Tycho and Kepler, and the tools provided by mathematicians 

 from Euchd to Descartes, with very essential additions of 

 his own. We are not less astonished, and almost over- 

 whelmed, by the countless number of single achievements, 

 which, from whatever side the work is regarded and studied, 

 are revealed to anyone capable of comprehending them. 

 The whole, when we consider the richness of its contents, 

 the general and detailed form, and the impression it makes 

 of towering greatness, can only be compared to a grand 

 old Gothic cathedral: one stands in front of it filled with 

 astonishment, absorbed in gazing at it, and without words 

 to express one's impressions. Great cathedrals were built 

 in numbers by the masters of Gothic; but among the works 

 of men of science, Newton's Principia is unique of its kind. 

 The artist is in a different position from that of the man of 

 science; he can create and work from his own mind without 

 limits, and in so far as he possesses the necessary materials, 

 he will always produce work corresponding to the greatness 

 of his powers. But the scientific investigator depends in 

 his work, apart from the favourableness or otherwise of 

 external circumstances, upon the laborious and exhaustive 



