Relativity
The Special and General Theory

of specifications of position must always be sought in accordance with the above considerations.^[4]

We thus obtain the following result: Every description of events in space involves the use of a rigid body to which such events have to be referred. The resulting relationship takes for granted that the laws of Euclidean geometry hold for "distances;" the "distance" being represented physically by means of the convention of two marks on a rigid body.

[4] A refinement and modification of these views does not become necessary until we come to deal with the general theory of relativity, treated in the second part of this book.