 The pluralism of Anaxagoras and Empedocles maintained the Eleatic strictures on metaphysically acceptable basic entities (things that are and must be just what they are) by adopting an irreducible pluralism of stuffs meeting these standards that could pass on their qualities to items constructed from them. Ancient atomism responded more radically: what is real is an infinite number of solid, uncuttable (atomon) units of matter. All atoms are made of the same stuff (solid matter, in itself otherwise indeterminate), differing from one another (according to Aristotle in Metaphysics 985b4-20=DK67A6/LM27D31 and R38) only in shape, position, arrangement. Later sources say that atoms differ in weight; some scholars have argued that, while this is certainly true for post-Aristotelian atomism, it is less likely for Presocratic atomism. Recent scholarship has questioned this view, and find no reason to deny weight to Presocratic atomism (Augustin 2015). In addition to the reality of atoms, the Presocratic atomists, Leucippus and Democritus (Democritus was born in about 460 BCE in Abdera in Northern Greece, shortly after Socrates was born in Athens), enthusiastically endorsed the reality of the empty (or  void).[11]  The void is what separates atoms and allows for the differences noted above (except weight, which could not be accounted for by void, since void in an atom would make it divisible and, hence, not an atom) (Sedley 1982; see also Sedley 2008). 