The problem comes up because we ask the question in the wrong way. We supposed that solids were one thing and space quite another, or just nothing whatever. Then it appeared that space was no mere nothing, because solids couldn't do without it. But the mistake in the beginning was to think of solids and space as two different things, instead of as two aspects of the same thing. The point is that they are different but inseparable, like the front end and the rear end of a cat. Cut them apart, and the cat dies.