56 TIME 



The scientist's interest in the absoluteness of this 

 velocity is very great; the philosopher's interest has 

 been, I think, largely a mistaken interest. In asserting 

 its absoluteness scientists mean that they have assigned 

 the same number to it in every measure-system; but 

 that is a private arrangement of their own — an un- 

 witting compliment to its universal importance.* Turn- 

 ing from the measure-numbers to the thing described 

 by them, the "grain" is certainly an absolute feature 

 of the wood, but so also are the "worm-holes" 

 (material particles). The difference is that the grain is 

 essential and universal, the worm-holes casual. Science 

 and philosophy have often been at cross-purposes in 

 discussing the Absolute — a misunderstanding which is 

 I am afraid chiefly the fault of the scientists. In science 

 we are chiefly concerned with the absoluteness or relativity 

 of the descriptive terms we employ; but when the term 

 absolute is used with reference to that which is being 

 described it has generally the loose meaning of "uni- 

 versal" as opposed to "casual". 



Another point on which there has sometimes been a 

 misunderstanding is the existence of a superior limit to 

 velocity. It is not permissible to say that no velocity can 

 exceed 299,796 kilometres per second. For example, 

 imagine a search-light capable of sending an accurately 

 parallel beam as far as Neptune. If the search-light is 

 made to revolve once a minute, Neptune's end of the 

 beam will move round a circle with velocity far greater 

 than the above limit. This is an example of our habit 

 of creating velocities by a mental association of states 



* In the general relativity theory (chapter vi) measure-systems are 

 employed in which the velocity of light is no longer assigned the same 

 constant value, but it continues to correspond to the grain of absolute 

 world-structure. 



