304 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



Now it seems to be a fact in recent physics that the 

 inadequacy of absolute space and absolute time has been 

 disclosed through both methods. It has been shown that 

 the existence of such entities is highly conjectural, on the 

 one hand, because there is no technique by which they 

 could be derived; by operations which are relative it is 

 hardly possible to derive something which is absolute. But 

 it has also been shown, on the other hand, that such entities 

 must be conjectural because the deductions from them do 

 not always coincide with facts; the outstanding illustration 

 is, of course, the famous Michelson-Morley experiment. 

 Hence through both routes attention has been called to the 

 possible inadequacy of the classical space and time systems. 



Reference will be made here only to the former of these 

 routes, since the concern throughout the chapter has been 

 with derivation rather than with verification. From this 

 point of view it seems possible to say in general that a 

 reexamination of the operational techniques employed in the 

 passage from empirical space and time to classical space and 

 time discloses certain questionable assumptions. As a result, 

 a modification of the classical point of view seems advisable. 

 The outcome of this modification is the space-time of rela- 

 tivity, whose outstanding feature is a "closer" connection 

 with empirical space and time. The justification of this 

 assertion will be found in the following paragraphs, which 

 will conclude the present chapter. 



Relativity. It seems obvious that the space-time of rela- 

 tivity will exhibit relativity as its most characteristic feature. 

 Yet a word of caution is necessary. To show that a thing 

 is relative is to show that it possesses certain of its features 

 by virtue of something else with which it is connected. 

 For example, A may possess the property p not in itself 

 but only in relation to B ; in relation to C it may possess the 

 property q. But this determines something absolute, viz., 

 the law according to which the properties of A change from 

 p to q as it is considered successively in its relations to B and 

 C. There are two senses in which space-time is relative. 



