44 THE LIMITATIONS OF SCIENCE 



essential to the progress of science. I shall try to show 

 that they are characterized by the same occult and 

 unverifiable assumptions as the older theories and are 

 really extra-scientific. 



Professor Larmor, in the beginning of his essay, 

 recognizes that an hypothesis which supposes matter 

 to be constituted of an immense number of discrete 

 particles moving in empty space and incapable of fur- 

 ther subdivision has a philosophical objection too diffi- 

 cult to be overcome. In the first place, as Lord Kelvin 

 pointed out, the chemical atom cannot be the immeasur- 

 ably small body sometimes claimed by metaphysicians. 

 Both physical and chemical experience require the atom 

 to be a real portion of matter occupying a finite space, 

 and forming a not inappreciably small constituent of 

 any palpable body. The chemical molecule may be 

 decomposed into the atoms of hydrogen and oxygen, 

 and now these atoms are in turn divided into sub- 

 atoms. Even these also are by no means immeasurably 

 small; we are already calculating their size and their 

 mass. And we can think of no reason why matter 

 should have been created of this size rather than any 

 other. These minute grains still have much individual- 

 ity of their own in the way of attributes; if electrified, 

 their mass is supposed to change in quantity when they 

 move, as does also their shape; they must explain 

 electrical attraction and repulsion, gravitational at- 

 traction, cohesion, and a probable molecular repulsion 



