The Origin of Epicurus' Concept of Void

Vacuum: a void full of questions

“…' As I can understand it, Aristotle emphasizes the fact that after the mover has imparted the impulse to the thing (X) moved, the former is no longer in contact with the latter. Therefore, in order for the movement to continue, either (i) the impulse received by X is first transferred to produce a series of compressions or reactions (I would suggest that either term, rather than 'cyclical replacement', is the translation of antiperístasin) [10] of the surroundings, from the subsequent expansion of which it receives the impulse back. (Ross [11] gives a more articulated and detailed analysis of this process, and relates the phrase 'as some say' to Plato's account of human respiration, Timaeus 79 a-b, in which the absence of any vacuum is stated twice), or (ii) X is sustained in its trajectory thanks to the action of the air it replaces.…”

“…On the other, Inwood holds that according to Epicurus a body's place is the surrounding vacuum, an idealized fluid. [10] However, there is unanimous consensus among scholars that Epicurus knew Aristotle's interpretation, [4,10,12] which inaccurately equated the Atomists' definition of vacuum to 'a sort of place' (see Section on Aristotle). [4] Aristotle's criticisms are, in a sense, a new challenge against the metaphysical and logical tenability of vacuum, especially against the apparent paradox inherent in the Atomists' scheme that both 'the non-existent' and 'the nothing' are essential constituents of reality.…”

“…[4] In order to assert the existence of a vacuum, Epicurus proposed arguments of his own, lying outside the legacy of mainstream Atomism. [4,10] His most strategic move was to drop the early Atomists' view that a vacuum is non-existent or is nothing, that is, a 'negative' view, and he replaced it with the view that vacuum is an 'intangible nature' (anaphes phusis). [4,6,12,13] As a consequence, vacuum is now endowed with 'positive' properties, the most important of which is its ability to subsist as a medium, and to yield to an atom (or a body).…”

“…In particular, his thought-out concept of vacuum allows atoms and bodies to move through it, overcoming the absurdities lamented by Aristotle to have two things in the same place. [4,10] Furthermore, Epicurean vacuum makes it possible for the same objects to move along a well-defined direction. As a result, Aristotle's criticisms against locomotion in Democritean vacuum are also overcome.…”

“…As a result, Aristotle's criticisms against locomotion in Democritean vacuum are also overcome. [4,10] The Stoics (4th century B.C. to 2nd century A.D.)…”