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Single Idea 5116

[filed under theme 27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement ]

Full Idea

Examples of unnatural movements are something earthy moving upwards and fire moving downwards. …When they are moved unnaturally it is obvious what they are moved by, but this is not obvious in the case of their natural movements.

Gist of Idea

When there is unnatural movement (e.g. fire going downwards) the cause is obvious

Source

Aristotle (Physics [c.337 BCE], 254b21)

Book Ref

Aristotle: 'Physics', ed/tr. Waterfield,Robin [OUP 1996], p.196

A Reaction

Aristotle always struggles when he tries to give an account of 'unnatural' events. It is hard to see how it is unnatural when a wind blows a flame down, or volcanoes blow earth up. There is hardly a natural distinction of causes which are 'obvious'.

The 32 ideas with the same theme [explaining why not all things are stationary]:

1713 Thales must have thought soul causes movement, since he thought magnets have soul [Thales, by Aristotle]
12269 All things are in a state of motion [Heraclitus, by Aristotle]
5115 It is feeble-minded to look for explanations of everything being at rest [Aristotle on Parmenides]
455 That which moves, moves neither in the place in which it is, nor in that in which it is not [Zeno of Elea]
3059 There is no real motion, only the appearance of it [Melissus, by Diog. Laertius]
24044 Movement can be intrinsic (like a ship) or relative (like its sailors) [Aristotle]
24045 Movement is spatial, alteration, withering or growth [Aristotle]
1738 Practical reason is based on desire, so desire must be the ultimate producer of movement [Aristotle]
1739 If all movement is either pushing or pulling, there must be a still point in between where it all starts [Aristotle]
399 If the more you raise some earth the faster it moves, why does the whole earth not move? [Aristotle]
20063 Motion fulfils potentiality [Aristotle]
5114 If movement can arise within an animal, why can't it also arise in the universe? [Aristotle]
5116 When there is unnatural movement (e.g. fire going downwards) the cause is obvious [Aristotle]
3063 Motion can't move where it is, and can't move where it isn't, so it can't exist [Pyrrho, by Diog. Laertius]
5696 If there were no space there could be no movement, or even creation [Lucretius]
5706 Atoms move themselves [Lucretius]
22747 A man walking backwards on a forwards-moving ship is moving in a fixed place [Sext.Empiricus]
1899 Does the original self-mover push itself from behind, or pull itself from in front? [Sext.Empiricus]
1900 If time and place are infinitely divided, it becomes impossible for movement ever to begin [Sext.Empiricus]
1901 If all atoms, times and places are the same, everything should move with equal velocity [Sext.Empiricus]
17234 Motion is losing one place and acquiring another [Hobbes]
15866 Newton reclassified vertical motion as violent, and unconstrained horizontal motion as natural [Newton, by Harré]
12484 Motion is just change of distance between two things [Locke]
12985 Maybe motion is definable as 'change of place' [Leibniz]
19348 All that is real in motion is the force or power which produces change [Leibniz]
12696 Bodies are recreated in motion, and don't exist in intervening instants [Leibniz]
4786 Russell's 'at-at' theory says motion is to be at the intervening points at the intervening instants [Russell, by Psillos]
14168 Occupying a place and change are prior to motion, so motion is just occupying places at continuous times [Russell]
15243 We perceive motion, and not just successive occupations of different positions [Harré/Madden]
20365 We only see points in motion, and thereby infer movement [Rescher]
4224 If motion is change of distance between objects, it involves no intrinsic change in the objects [Lowe]
14725 Maybe motion is a dynamical quantity intrinsic to a thing at a particular time [Sider]