 The doctrine of  Atomism,[8]  which seems to have arisen as an attempt at escaping the Eleatic dilemma, was first and foremost a physical theory. It was mounted by Leucippus (fl. 440 BCE) and Democritus (b. 460–457 BCE) who maintained that matter was not divisible without limit, but composed of indivisible, solid, homogeneous, spatially extended corpuscles, all below the level of visibility.