 Hero of Alexandria’s matter theory has long been considered an important source for Robert Boyle and other New Scientists of the seventeenth century (Boas 1949). However, Hero’s theory differed from classical atomism, and drew heavily on the need to explain pneumatic effects (see section 2.6 above). The evidence of Sennert’s influence on Boyle casts further doubts on the centrality of ancient Greek atomism to his matter theory. Newman (2006, 2009) argues that the relevant sense of ‘atom’ depended on the incapacity for chemical decomposition, not spatial or physical indivisibility, a notion grounded in empirical evidence rather than logical or mathematical reasoning.