.[7] The principle of the constancy of the velocity of light then states that this adjustment of the clocks will not lead to contradictions. With clocks so adjusted, we can assign the time to events which take place near any one of them. It is essential to note that this definition of time relates only to the inertial system
, since we have used a system of clocks at rest relatively to
. The assumption which was made in the pre-relativity physics of the absolute character of time (i.e. the independence of time of the choice of the inertial system) does not follow at all from this definition.
[7]Strictly speaking, it would be more correct to define simultaneity first, somewhat as follows: two events taking place at the points
and
