  Not all of the mechanical philosophers were mechanical atomists. Descartes provides a ready example of a mechanical philosopher who was not an atomist insofar as he rejected the void and held that particles of matter could be broken down into smaller particles. The mechanical philosophers were divided on the question of the existence of the void, some sharing the opinion of the Greek atomists that void was a pre-requisite for motion but others, like Descartes, rejecting the void as unintelligible and hence regarding all motion as involving the simultaneous displacement of closed loops of matter whether that matter be continuous or particulate. Arguments at the most general level for the intelligibility of the void and its relation to the possibility of motion were inconclusive. In addition to the question of the void, there is the question of whether matter is particulate and whether there are indivisible particles called atoms. Once again, general a priori philosophical arguments were hardly able to settle the question.