Nevertheless, Descartes’ hypothesis of motion may sanction a species of relative motion, since his phrase, “considered at rest”, implies that the choice of which bodies are at rest or in motion is purely arbitrary. According to the “relational” theory (or at least the more strict versions of relationism), space, time, and motion are just relations among bodies, and not separately existing entities or properties that are in any way independent of material bodies. Motion only exists as a “relative