EM A NCIPA TION FROM SCIENTIFIC MA TERIALISM. 423 



strangeness, indeed its absurdity. But if we consider for 

 a moment that all we know of a given substance consists 

 in the knowledge of its properties it is evident that the 

 assertion that a certain substance continues to exist without 

 possessing these properties is not very far removed from 

 pure nonsense. As a matter of fact, this purely formal 

 assumption serves simply to unite the general facts of 

 chemistry, in particular the stochiometric laws of mass, 

 with the arbitrary notion of an intrinsically unvarying 

 matter. 



But even the so extended idea of matter, together with 

 the necessary attendant suppositions, is not sufficient to 

 embrace all phenomena, not even indeed in the inorganic 

 world. We think of matter as something in itself in- 

 trinsically motionless and unvarying ; hence in order to 

 make the representation of an ever-changing world possible, 

 we must supplement this conception with another inde- 

 pendent one which gives expression to this changeableness. 

 A conception of this sort was, in the most successful manner, 

 developed by Galileo, the founder of scientific physics, in 

 the idea of force as the constant cause of motion. Galileo 

 had, in fact, discovered an invariant of great importance for 

 the varying phenomena of free and indirect fall ; and with the 

 assumption of the intrinsically constant force of gravita- 

 tion, whose effects continuously accumulate, the complete 

 representation of these phenomena became possible. The 

 significance of this conception became evident when 

 Newton, with his idea that the same force acted between 

 the heavenly bodies, brought the whole star-world under 

 the sway of science. It was this step forward in particular 

 which gave rise to the conviction that just as the astronom- 

 ical so also all other physical phenomena must be capable 

 of representation by this means. When, moreover, at the 

 beginning of our century the efforts of numerous, and 

 especially French, astronomers had shown that Newton's 

 law of gravitation could not only represent the motions 

 of the heavenly bodies to a first approximation, but with- 

 stood also the far severer test of a second approximation in 

 their ability to express with equal certainty and accuracy the 



