THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SEMES.] 



JULY 1893. 



I. The Foundations of Dynamics. By Olivek Lodge, F.R.S., 

 Professor of Physics in University College, Liverpool*. 



Paet I. — The Nature of Axioms . 



IT is a matter of congratulation with me that a critic who 

 has devoted so much thought to Newton's laws of motion 

 and similar fundamental doctrines should have begun a dis- 

 cussion of my papers on the subject of Energy ; and I shall 

 willingly consider his objections in order to see what modifi- 

 cations, if any, should be made in my original statements. 

 But Dr. MacGregor's temporary attitude towards Physical 

 problems is exhibited rather strikingly in a treatise on " The 

 Fundamental Hypotheses of Abstract Dynamics," which he 

 published as a Presidential Address to a section of the Royal 

 Society of Canada (Transactions 1892) . Hence, before replying 

 to his criticisms on my writings, as made in your February 

 issue, page 134, I should like to make a few general observa- 

 tions suggested by this other deliverance of his, so as to indi- 

 cate what seem to me the rather different points of view from 

 which we, or if not we some other writers, approach these 

 fundamental doctrines of Mechanics and Physics. The dif- 

 ference in attitude may be briefly summarised thus : — Some 

 philosophers seek to advance truth by detecting or inventing 

 complications in what was apparently simple ; whereas others 

 aim at making simple statements concerning things which are 

 apparently or really complicated. A generalization like this is 



* Communicated by the Physical Society : read May 12, 1893. 

 Phil Mag. S. 5. Yol. 36. No. 218. July 1893. B 



