It is indeed an exacting requirement to have to ascribe physical reality to space in general, and especially to empty space.

“now” loses for the extended world its objective meaning … .

According to the theory of relativity, action at a distance with the velocity of light always takes the place of instantaneous action at a distance or of action at a distance with an infinite velocity of transmission.

(G)eometry however is not concerned with the relation of the ideas involved in it to objects of experience, but only with the logical connection of these ideas among themselves.

Who would imagine that this simple law has plunged the conscientiously thoughtful physicist into the greatest intellectual difficulties.

[I]n the theory of [special] relativity the velocity c plays the part of a limiting velocity, which can neither be reached nor exceeded by any real body.

… a spacious chest resembling a room with an observer inside [to which] is fixed externally a hook with rope attached …

… a big castle in the air that I’ve built you.