Leibniz describes a space that exists only as a relation between <answer>objects</answer>, and which has no existence apart from the existence of those <answer>objects</answer>. Motion exists only as a relation between those <answer>objects</answer>. Newtonian space provided the absolute frame of reference within which <answer>objects</answer> can have motion. In Newton's system, the frame of reference exists independently of the <answer>objects</answer> contained within it. These <answer>objects</answer> can be described as moving in relation to space itself. For many centuries, the evidence of a concave water surface held authority.
Leibniz describes space as existing only as a relation between what?
objects