Retracing the Ancient Steps to Atomic Theory

Much can be learnt about the character of modern science from a study of the history of atomism, not because of the extent to which modern conceptions and arguments are anticipated in that history, but because of the ways in which those historical theories and practices differed qualitatively from contemporary theory and practice. The atomism of Democritus differed from contemporary atomic theory more than is typically appreciated. In the seventeenth century something like Democritean atomism was revived by Boyle and Newton, but not in a form that brought it significantly closer to modern atomic theory. The first version of atomism that was able to support an empirical programme was proposed by Dalton early last century, but even this lacked the direct support from experiment and fell well short of realisation that a crucial aspect of atoms is their internal structure.