"Being" opposed to "Not being"

For Greek Philosophers opposed 'being' was opposed to 'not being'. Change was impossible, because it would mean that something that was 'not being' changed into 'being', which was considered absurd. As explained by Hegel, in his lectures on Greek Philosophy, being and non-being, as something thought, which, when represented for consciousness as differing in regard to one another, are the plenum and the vacuum, have no diversity in themselves; for the plenum has likewise negativity in itself; as independent, it excludes what is different; it is one and infinitely many ones, while the vacuum is not exclusive, but pure continuity.

In particular Parmenides postulated that a void, essentially what is now known as a vacuum, in nature could not occur. This view was supported by Aristotle, Al-Farabi, Hobbes, Descartes, Leibniz, Maupertius, Kant, Birkeland and others, but was criticized by Leucippus, Hero of Alexandria, Ibn al-Haytham and others.

The atomic ideas of Leucippus and Democritus around 440 BC were opposed by Aristotle about 100 years or so later. But the atom and the vacuum are not things of experience; Leucippus says that are not the senses through which we become conscious of the truth.

Democritus asserted that space, or the Void, had an equal right with reality, or Being, to be considered existent. He conceived of the Void as a vacuum, an infinite space in which moved an infinite number of atoms that made up Being. These atoms are eternal and invisible; absolutely small, so small that their size cannot be diminished; absolutely full and incompressible, as they are without pores and entirely fill the space they occupy; and homogeneous, differing only in shape, arrangement, position, and magnitude.

With this as a basis to the physical world, Democritus could explain all changes in the world as changes in motion of the atoms, or changes in the way that they were packed together. This was a remarkable theory which attempted to explain the whole of physics based on a small number of ideas and also brought mathematics into a fundamental physical role since the whole of the structure proposed by Democritus was quantitative and subject to mathematical laws.

There are then questions for Democritus to answer. Where do qualities such as warmth, colour, and taste fit into the atomic theory? To Democritus atoms differ only in quantity, and all qualitative differences are only apparent and result from impressions of an observer caused by differing configurations of atoms. The properties of warmth, colour, taste are only by convention - the only things that actually exist are atoms and the Void.

Democritus's philosophy contains an early form of the conservation of energy. In his theory atoms are eternal and so is motion. Democritus explained the origin of the universe through atoms moving randomly and colliding to form larger bodies and worlds. There was no place in his theory for divine intervention. Instead he postulated a world which had always existed, and would always exist, and was filled with atoms moving randomly. Vortex motions occurred due to collisions of the atoms and in resulting vortex motion created differentiation of the atoms into different levels due only to their differing mass. This was not a world which came about through the design or purpose of some supernatural being, but rather it was a world which came about through necessity, that is from the nature of the atoms themselves.

“The full is nothing simple, for it is an infinitely manifold. These infinitely many, move in the vacuum, for the vacuum exists; their conglomeration brings about origination”, “disintegration and separation result in passing away.” “Activity and passivity subsist in the fact, that they are contiguous; but their contiguous not their becoming one, for from that which is truly”; “one there does not come a number, nor from that which is truly many, one.” Or, it may be said, they are in fact neither passive nor active, “for they merely abide through the vacuum” without having as their principle, process. Atoms thus are, even in their apparent union in that which we call things, separated from one another through the vacuum which is purely negative and foreign to them, i.e. their relation is not inherent in themselves, but is with something other than them, in. which they remain what they are. This vacuum, the negative in relation to the affirmative, is also the principle of the movement of atoms; they are so to speak solicited by the vacuum to fill up and to negate it.

Hero of Alexandria then in 150 A.D. made use of atoms to explain compression and rarefaction. Hero denied the existence of an extended vacuum, but allowed for a vacuum between atoms. One proof he cited was that fire could enter into a material, showing that it had openings, i.e., a vacuum. He pointed out that the pores of a diamond were too small to let in fire and so the stone was incombustible.