Concepts of Space in Greek Thought

Vacuum: a void full of questions

“…a just action. [6] The noun which kenós modifies is the main backdrop for the various ancient views of a vacuum. In the course of the paper I will always use the term 'vacuum', although 'void' is probably a better translation of kenós (and it is often used in scholarly studies of Greek philosophy), [3 -6] because surface scientists are far more familiar with the former than with the latter.…”

“…The first such example was given by Melissus (5th century B.C.). In order to assert that 'Being' (toón) is one, immutable, homogeneous, eternal, among other things, he says (translation by Sedley): [4] ' [6] as Melissus propounded it as a follower of Parmenides, the chief representative of the Eleatic school.…”

“…They argued that, for a comprehensive understanding of the universe, vacuum is as indispensable as bodies (the atoms and clusters thereof) because it gives the latter a way to move, agglomerate and separate: that is, the formation of the world and the changes therein involved. [6] To describe the dualistic nature of reality, the Atomists used three interchangeable pairs [4] : the first pair is 'the existent' (toón) and the 'non-existent' (to meón), whereas the second is 'the thing' (to den) and 'the nothing' (to meden). Sedley [4] explains that both these pairs 'can only be understood as designations of that which occupies space.'…”

“…He held that during the neverceasing Becoming of the sensible world, interstices or pockets of empty space may well form between adjoining elemental solids. [7] However, such gaps (also Strato, one of Aristotle's successors, believed in interstices or pores of vacuum) [6,8] must be considered not as an uncontroversial evidence for Plato's assertion of the existence of a vacuum. Rather, they should be thought of as just accidental 'by-products' of the Becoming, since they have none of the metaphysical or geometrical functions the Atomists ascribed to vacuum.…”

“…[9] Aristotle also sets out a series of arguments that concern the impossibility of locomotion, either natural or forced, in a vacuum. [6,8] Some salient points of one such argument run thus (translation by Hussey): [9] 'Though some say that there is void because it is necessary if it there be change, in fact, if one considers carefully, it is rather the opposite that results: that if there is void it is not possible for anything to move. .…”