SCIENCE AS A SYMBOL AND A LAW 5 



philosophical scientists of the French revolutionary 

 period, with whom this mechanistic movement cul- 

 minated, had only mechanical problems to work on, in 

 which their knowledge was practically as accurate as it 

 is to-day. 



However we may regard the effect of the metaphys- 

 ical system of Descartes on science, there can be only 

 one opinion as to the value of his introduction of geom- 

 etry into physics. By it, he changed medieval natural 

 philosophy into modern physics. When he discovered 

 the method of locating the position of any point by 

 giving its distance from three rectangular straight 

 lines, he made it possible to represent the path of any 

 moving body by a geometrical line referred to the same 

 axes, which could then be fully defined by an algebraic 

 equation; he thus made it possible to classify all mo- 

 tions under a few general types, and so founded the 

 science of kinematics. For example, it became no 

 longer necessary to study projectiles individually, for 

 their behavior could be foretold from the general prop- 

 erties of parabolas. Shortly after this, Newton and 

 Leibnitz invented the calculus, which enables us to study 

 moving bodies during their transit. The solution of 

 problems of continuous motion in curved lines could 

 never be satisfactorily obtained by Euclidean geometry, 

 which could not overcome the break between rest and 

 motion, or between polygons and curves. But the 

 application of the infinitesimal calculus to Cartesian 



