"How far away from the earth are those remotest of stars: they are beyond the reach of eye, or man's devices, or man's thought. What an absurdity is this motion (of spheres). He also argues for the extreme variability of the distance to the various heavenly bodies and states that situated "in thinnest aether, or in the most subtle fifth essence, or in vacuity - how shall the stars keep their places in the mighty swirl of these enormous spheres composed of a substance of which no one knows aught?"