| 13217 | The void can't exist, and without the void there can't be movement or separation [Parmenides, by Aristotle] |
| Full Idea: Some philosophers thought what is must be one and immovable. The void, they say, is not: but unless there is a void what is cannot be moved, nor can it be many, since there is nothing to keep things apart. | |
| From: report of Parmenides (fragments/reports [c.474 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 325a06 | |
| A reaction: Somehow this doesn't seem very persuasive any more! I suppose we would distinguish various degrees of void, and assert the existence of sufficient void to allow movement and separation. We must surely agree that total nothingness doesn't exist. |
| 5100 | The void is not required for change, because a plenum can alter in quality [Aristotle on Melissus] |
| Full Idea: There is no need for void to be the cause of all change, because it is perfectly possible for a plenum to alter qualitatively (which is something Melissus overlooked). | |
| From: comment on Melissus (fragments/reports [c.443 BCE]) by Aristotle - Physics 214a27 | |
| A reaction: In modern physics this presumably gives us fluctuations in a force field. Motion is like a cat being digested by a python. The atomist claim that emptiness is needed if anything is to move still has intuitive appeal. |
| 24059 | Democritus is wrong: in a void we wouldn't see a distant ant in exact detail [Aristotle on Democritus] |
| Full Idea: Democritus did not speak correctly in supposing that if the intermediate space became a void, we would see an ant in exact detail if it were up in the heaven. …If the intermediate space became a void, rather nothing would be seen at all. | |
| From: comment on Democritus (fragments/reports [c.431 BCE]) by Aristotle - De Anima 419a15 | |
| A reaction: Depends what you mean by void, but Aristotle is nearer the truth. Is vision clearer in outer space than in our higher atmosphere? |
| 5101 | Movement is impossible in a void, because nothing can decide the direction of movement [Aristotle on Democritus] |
| Full Idea: Void makes it impossible for anything to move, since in a void there is nowhere for a thing to move to more or less than anywhere else, because the void by definition contains no differentiation. | |
| From: comment on Democritus (fragments/reports [c.431 BCE]) by Aristotle - Physics 214b32 | |
| A reaction: A lovely application of the Principle of Sufficient Reason. However this assumes that the cause of the movement is going to be in the void (telos?), rather than in the body which will move (modern causation?). |
| 20905 | Growth and movement would not exist if there were no void to receive them [Democritus] |
| Full Idea: They say that one argument for void is that otherwise local motion (that is, locomotion and growth) would not exist: for there would not seem to be motion if there were no void, for what is full is incapable of receiving anything. | |
| From: Democritus (fragments/reports [c.431 BCE], A019), quoted by Aristotle - Physics 213b03 | |
| A reaction: The modern concept of a 'field' seems to have removed the possibility of a genuine 'void'. |
| 20918 | Void is a kind of place, so it can't explain place [Aristotle] |
| Full Idea: It is absurd to explain place by the void, as though this latter were not itself some kind of place. | |
| From: Aristotle (On the Heavens [c.336 BCE], 309b24) | |
| A reaction: Presumably this is aimed at Democritus. |
| 14043 | The void cannot interact, but just gives the possibility of motion [Epicurus] |
| Full Idea: The void can neither act nor be acted upon but merely provides the possibility of motion through itself for bodies. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 67) | |
| A reaction: Epicurus follows this with the anti-dualist Idea 14042, but he is at least offering the notion of something which exists without powers of causal interaction. Does space undermine the causal criterion for existence? |
| 20822 | There is no void in the cosmos, but indefinite void outside it [Zeno of Citium, by Ps-Plutarch] |
| Full Idea: Zeno and his followers say that there is no void within the cosmos but an indefinite void outside it. | |
| From: report of Zeno (Citium) (fragments/reports [c.294 BCE]) by Pseudo-Plutarch - On the Doctrine of the Philosophers 884a | |
| A reaction: Only atomists (such as Epicureans) need void within the cosmos, as space within which atoms can move. What would they make of modern 'fields'? Posidonius later said there was sufficient, but not infinite, void. |