NEWTON 's THEORY or PLANETARY MOTIONS 79 



showing that natural law does not even rise to the height 

 of the physical heavens ! 



A little sober reflection ought to convince anyone that 

 attempts to solve the problems of the cosmos by adopting 

 in the outset a group of "laws" transcending, and even 

 contradicting, human experience, and, with these as a 

 base, trying to harmonize celestial phenomena in other 

 respects interpreted by mundane standards must prove 

 abortive. Natural law is consistent with itself from the 

 greatest to the least; pervert one part of it and you in- 

 volve yourself in an endless maze of error. Were the 

 matter less serious, it would be amusing to note the airs 

 assumed by astronomers at having "discovered" this 

 supposed departure of celestial from terrestrial me- 

 chanics this inconsistency of Dame Nature, the chief of- 

 fender of her sex. Thus we find Miss Mary Agnes Clerke 

 the distinguished historian of astronomy (Modern Cos- 

 mogonies, p. 10) writing naively: Kepler's ignorance 

 of the laws of motion precluded him from the conception 

 of velocities persistent in themselves, and merely de- 

 flected from straight lines into curved paths by a constant 

 central pull." Let it once be contended that mechanical 

 effects, such as the rectilinear motions of stars and 

 planets undoubtedly are, exist independently of physical 

 causation, and you commit four grave follies; (1) You 

 deprive physical science of the only ground she has to 

 stand upon, namely, the law of physical cause and effect, 

 the sole key to the interpretation of nature; (2) You 

 throw wide the door to the perpetration of all sorts of 

 other pious frauds ; for if Nature departs from her laws 

 in one case, why may she not do so in any other, accord- 

 ing to the exigency of theory or the whim of any of her 

 would-be interpreters'? (3) You commit yourself ir- 

 revocably to the hopeless task of trying to correlate facts 

 with miracles, instead of facts with cognate facts ; and 

 (4) You require of the present order of Nature not only 

 to regulate itself, but likewise to overcome and discipline 

 the erratic elements left over or inherited from a pre- 

 vious state of chaos. 



