KINETIC OR MECHANICAL VIEW OF NATURE. 



one of those convenient resting-places, those preliminary 

 or provisional bases of thought, from which definite prob- 

 lems could be attacked and solved. His immediate 

 influence lay, therefore, rather in discountenancing the 

 attempts towards a kinetic view of nature, which belonged 

 to the school of Descartes, and found an eminent exponent 

 in Huygens as well as in others of his contemporaries and 

 rivals ; l in fact, he launched into existence what I have 

 termed the astronomical view of nature, under the sway 

 of which the promising beginnings of the kinetic view 

 were for a long period almost forgotten, but which has 

 the merit of having built up the most perfect of all 

 physical sciences, namely, physical astronomy. 



The sporadic beginnings of a genuine kinetic view of 

 natural phenomena, after having been cultivated with 

 more or less success by Huygens and Euler, 2 and early 



3. 

 Huygens 



i of 



century! 



1 Among these, of whom Lasswitz 

 gives an exhaustive account, must 

 be mentioned specially Robert 

 Hooke (1635-1703). "In the his- 

 tory of the corpuscular theory Hooke 

 represents quite an original idea, 

 which would have been of the most 

 far-reaching importance if Hooke 

 himself had got beyond a mere 

 sketch to an exhaustive theory, or 

 if his conceptions had, through 

 Huygens' principles of dynamics, 

 been domiciled in science. The 

 deviation from kinetic theories 

 caused by Newton's discoveries 

 brushed away, with much useless 

 hypothetical rubbish, likewise 

 Hooke's more valuable and legiti- 

 mate suggestion*. The doctrine 

 owing to which we place Hooke 

 between Borelli and Huygens is his 

 vibratory theory of matter. It is 

 given in various writings, but most 

 clearly in his Lectures ' De Potentia 

 Restitutiva, or of Spring explaining 



the Power of Springing Bodies,' 

 London, 1678 " (op. cit., vol. ii. p. 

 329 sq.) 



2 Leonhard Euler (1707-83), 

 one of the greatest analytical 

 talents of all times, whose writings 

 contain the beginnings of a very 

 large portion of subsequent mathe- 

 matical work in pure and applied 

 science, was in physics a great 

 opponent of Newton's philosophy 

 as it was then generally expounded 

 on the continent of Europe. There 

 it was identified in mechanics 

 with the theory of action at a 

 distance, and, in optics, with the 

 corpuscular theory of light. To 

 both Euler opposed his ether 

 theory, of which he gave a popular 

 account in his celebrated ' Lettres a 

 une princesse d'Allemagne [Princess 

 of Anhalt - Dessau] sur quelques 

 sujets de physique et de philoso- 

 phic ' (Petersburg, 1768-72, 3 parts). 

 He had given a scientific exposi- 



