“Absolute space is conceived as remaining always similar to itself and immovable. The arrangements of the parts of space can no more be altered than the order of the portions of time. To conceive them to move from their places is to conceive a place to move away from itself.
But as there is nothing to distinguish one portion of time from another except the different events which occur in them, so there is nothing to distinguish one part of space from another except its relation to the place of material bodies. We cannot describe the time of an event except by reference to some other event, or the place of a body except by reference to some other body. All our knowledge, both of time and of place is essentially relative.*
~James Clerk Maxwell (1831-1879)
*The position seems to be that our knowledge is relative, but needs definite space and time as a frame for its coherent expression.” (notes and appendices by Sir Joseph Larmor)