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Ideas for 'Dissoi Logoi - on Double Arguments', 'Physics' and 'works'

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3 ideas

27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Motion fulfils potentiality [Aristotle]
     Full Idea: Motion is the fulfilment of what exists potentially, in so far as it exists potentially.
     From: Aristotle (Physics [c.337 BCE], 201a10-11), quoted by Rowland Stout - Action 6 'Two'
     A reaction: We might put that as 'all motion is the fulfilment of a natural power'. But that gives the source of motion, and not its intrinsic nature.
If movement can arise within an animal, why can't it also arise in the universe? [Aristotle]
     Full Idea: Movement can arise within a motionless animal out of the object itself, rather than being due to some external agent. But why should this not also be true of the universe?
     From: Aristotle (Physics [c.337 BCE], 252b24)
     A reaction: A nice objection to the Unmoved Mover concept of God. Unfortunately it is ruined by the modern realisation that an animal is never 'motionless', because brain activity is continuous, and ceases only with death.
When there is unnatural movement (e.g. fire going downwards) the cause is obvious [Aristotle]
     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.
     From: Aristotle (Physics [c.337 BCE], 254b21)
     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'.