302 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



I recognize the essential irrelevance of spatial occupants; 

 space then begins to exhibit a permanent structure which is 

 independent of events. Analogously, through a recognition 

 of the fact that messages take time I realize that what is 

 ' 'now' for me may be "then' : for another, and what is 

 "then' for me may be 'now' for another. Furthermore, 

 when I find that an hour which for me was very exciting and 

 therefore very short can be correlated with an hour which 

 for another was very dull and therefore very long, I recognize 

 the essential irrelevance of temporal occupants; time then 

 begins to exhibit a permanent structure which is independent 

 of all processes. In some such way the hummocks, twistings, 

 and compressions of space and time are eliminated, and a 

 strictly homogeneous space and time result. 



From anisotropy to isotropy. Both the dimensional and 

 the directional features of isotropy are introduced into 

 empirical space and time through abstraction. The dimen- 

 sional anisotropy of empirical space is lost with the abandon- 

 ment of events. The uniqueness of the up-down dimension, 

 for example, lies, as was seen, in such things as gravitation, 

 our upright positions, the limitations of our movements 

 in this direction, etc.; when reference to one's body 

 and to other events is abandoned the uniqueness disappears. 

 The peculiarity of the near-far dimension can be eliminated 

 by the simple device of placing individuals in such a way 

 that what is for one a near-far dimension is for the other a 

 right-left dimension. The directional anisotropy can be 

 eliminated in a similar manner. To show the arbitrary char- 

 acter of the distinction between right-left and left-right, all 

 that is required is one individual facing another. By similar 

 techniques all directional features of space can be shown 

 to be dependent merely upon coordinate systems, and hence 

 arbitrary. The directional anisotropy of time is eliminated 

 when causal concerns are abandoned. Causation does not 

 seem to be inherent in the time scheme, but merely a feature 

 of events. The unthinkable character of a world in which 

 death precedes birth is not a matter of time itself but of 



