 A particular focus of Parmenides’ criticism, on this view, was Anaximander’s idea that the opposites are initially latent within the originative principle he called “the Boundless” (to apeiron) prior to being separated out from it: if these opposite characteristics existed prior to being separated out, then the Boundless was not a true unity, but if they did not exist prior to being separated out, then how could they possibly come into existence? It is thus illegitimate to suppose that everything came into being out of one thing (Guthrie 1962, 86–7). In addition to thus criticizing the theoretical viability of the monistic material principles of the early Milesian cosmologists, Parmenides also is supposed to have criticized the Milesian union of the material and moving cause in their principles by arguing that motion and change are impossible and inadmissible conceptions (Guthrie 1965, 5–6, 52).