THE ASTRONOMICAL VIEW OF NATURE. 



337 



physical actions, is, however, dependent on the mutual 

 distances of the particles of matter, and can therefore be 

 altered, but can as little as the existence of matter itself 

 be removed. This view of Newton's explained or de- 

 scribed clearly ^ the phenomena of moving and falling 



^ The distinction between an ex- 

 planation and a description of the 

 facts of nature has been slowly de- 

 veloped in the course of modern 

 thought. Probably Leibniz was 

 the first to insist on it, and to 

 maintain in the abstract that all 

 description of nature would be me- 

 chanical, but that the explanation or 

 interpretation of nature must be 

 spiritual. But the first practical 

 instance of this important distinc- 

 tion is really to be found in New- 

 ton's philosophy. In many jaas- 

 sages of the ' Principia,' and especi- 

 ally in the ' Optics,' the double view 

 of the problems of philosophy is 

 clearly indicated. The principles 

 of science since the time of Newton 

 are general facts, established by 

 experience and put into mathe- 

 matical language, admitting of con- 

 stant verification by observation 

 and by the deductions of the cal- 

 culus. These principles are not 

 the ultimate causes, but only a 

 concise description of some of the 

 phenomena of nature. These prin- 

 ciples Newton calls mathematical 

 referring to measurable quantities 

 and distinguishes them from the 

 philosophical principles ('Priuc. ,' 

 1st ed., p. 401). Especially as re- 

 gards gravitation, Newton explains 

 many times that he uses this term 

 not as an explanation, but only as 

 a mathematical description of the 

 force with which bodies approach 

 eacii other, whatever the cause of 

 this phenomenon may be, which he 

 leaves others (called with some 

 irony metaphysicians) to deter- 

 mine (' Optics,' query 31). That 



VOL. L 



Newton, besides giving the precise 

 mathematical principles of all future 

 dynamical science, indulged also in 

 further speculations, which he put 

 into the form of queries and ad- 

 vanced with hesitation and merely 

 tentatively, gave his opponents 

 ample opportunity to attack the 

 doubtful and uncertain statements 

 in his philosophj'. Instead of 

 studying and understanding the 

 mathematical truths of the ' Prin- 

 cipia,' they attacked the doctrines 

 which were fragmentarily put for- 

 ward in the queries to the ' Optics ' 

 or added in the general scholium 

 at the end of the second edition of 

 the 'Principia.' Roger Cotes in 

 his preface to the second edition 

 of the ' Principia,' and Clarke in 

 his correspondence with Leibniz, 

 pointed out the difference between 

 Newton's descriptive and calculat- 

 ing and the older or metaphysical 

 philosophy. They were, however, 

 more interested in disproving the 

 atheistical consequences of which 

 Newton's philosophy had been ac- 

 cused than in clearly insisting on 

 the fundamental difference between 

 mathematical and metaphysical 

 principles i.e., between the exact 

 and the philosophical views of na- 

 ture. And in Bentley's Boyle lec- 

 tures, delivered in 1692 and 1693, 

 the principles of Newton's philo- 

 sophy were specially brought for- 

 ward to refute atheism, an under- 

 taking which Newton himself sup- 

 ported in his contemporary corre- 

 spondence with Bentley, published 

 half a century later, in 1756. 



