282 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



external. . . . Absolute space, in its own nature, without 

 regard to anything external, remains always similar and 

 immovable." x One of Euclid's basic assumptions was the 

 legitimacy of moving figures from place to place; this pre- 

 sumed an independent character for space, and made its 

 nature in no way an effect of its occupant. Hence space and 

 time are considered from this point of view to be the back- 

 ground or stage-setting for events. Events may come and 

 go but time goes on forever; similarly events may be here 

 and there but space extends everywhere. 



Singleness. The singleness of space and time follows, 

 perhaps as a corollary, from their objectivity. If space and 

 time are independent of events, they are in no way tied up 

 with the peculiar content of my experience as over against 

 yours. Hence I have no right to conclude that my space and 

 time are different from yours. Though I always experience 

 spatial events as relative to my own body, and though I 

 always experience temporal events as relative to the stream 

 of my own individual consciousness, space and time as 

 such are subject to no such relativity. There is, in fact, only 

 one space, which is the space of all experiences, and only 

 one time, which is the tune of all experiences. We live, 

 therefore, in a common world whose structure is that of 

 space and time. The time which is here (say, on the earth) 

 is the same as the time which is there (say, on the moon) ; 

 the 'right" time is everywhere the same. Similarly, the 

 space which is now (say, 1937) is the same as the space 

 which will be at some later time (say, 2037): the "true" 

 space is always the same. Negatively, no individual is 

 isolated in his own spatial or his own temporal system. 

 Communication is possible precisely because of the inter- 

 section of private systems in a common space and common 

 time. 



Continuity. The notion of continuity as applied to space 

 and time is somewhat ambiguous. There are at least three 

 senses in which these aspects of nature may be said to be 



1 Newton's Principia, tr. by Motte (New York: Adee, 1846), p. 77. 



