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Ideas for 'fragments/reports', 'talk' and 'Principia Mathematica'

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7 ideas

26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / a. Final purpose
Covers are for shields, and sheaths for swords; likewise, all in the cosmos is for some other thing [Chrysippus]
     Full Idea: Just as the cover was made for the sake of the shield, and the sheath for the sword, in the same way everything else except the cosmos was made for the sake of other things.
     From: Chrysippus (fragments/reports [c.240 BCE]), quoted by M. Tullius Cicero - On the Nature of the Gods ('De natura deorum') 2.37
     A reaction: Chrysippus was wise to stop at the cosmos. Similarly, religious teleology had better not ask about the purpose of God. What does he think pebbles are for? Nature is the source of stoic value, so it needs to be purposeful.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / c. Ultimate substances
Newton's four fundamentals are: space, time, matter and force [Newton, by Russell]
     Full Idea: Newton works with four fundamental concepts: space, time, matter and force.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Bertrand Russell - My Philosophical Development Ch.2
     A reaction: The ontological challenge is to reduce these in number, presumably. They are, notoriously, defined in terms of one another.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
The later Stoics identified the logos with an air-fire compound, called 'pneuma' [Chrysippus, by Long]
     Full Idea: From Chrysippus onwards, the Stoics identified the logos throughout each world-cycle not with pure fire, but with a compound of fire and air, 'pneuma'.
     From: report of Chrysippus (fragments/reports [c.240 BCE]) by A.A. Long - Hellenistic Philosophy 4.4.2
     A reaction: I suspect this was because breath is so vital to the human body.
Fire is a separate element, not formed with others (as was previously believed) [Chrysippus, by Stobaeus]
     Full Idea: In his theory fire is said independently to be an element, since it is not formed together with another one, whereas according to the earlier theory fire is formed with other elements.
     From: report of Chrysippus (fragments/reports [c.240 BCE]) by John Stobaeus - Anthology 1.10.16c
     A reaction: The point is that fire precedes the other elements, and is superior to them.
Stoics say earth, air, fire and water are the primary elements [Chrysippus, by Plutarch]
     Full Idea: The Stoics call the four bodies - earth and water and air and fire - primary elements.
     From: report of Chrysippus (fragments/reports [c.240 BCE], fr 444) by Plutarch - 72: Against Stoics on common Conceptions 1085c
     A reaction: Elsewhere (fr 413) Chrysippus denies that they are all 'primary'. Essentially, though, he seems to be adopting the doctrine of Empedocles and Aristotle, in specific opposition to Epicurus' atomism.
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / a. Early Modern matter
Mass is central to matter [Newton, by Hart,WD]
     Full Idea: For Newton, mass is central to matter.
     From: report of Isaac Newton (Principia Mathematica [1687]) by William D. Hart - The Evolution of Logic 2
     A reaction: On reading this, I realise that this is the concept of matter I have grown up with, one which makes it very hard to grasp what the Greeks were thinking of when they referred to matter [hule].
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / b. Corpuscles
An attraction of a body is the sum of the forces of their particles [Newton]
     Full Idea: The attractions of the bodies must be reckoned by assigning proper forces to their individual particles and then taking the sums of those forces.
     From: Isaac Newton (Principia Mathematica [1687], 1.II.Schol)
     A reaction: This is using the parts of bodies to give fundamental explanations, rather than invoking substantial forms. The parts need not be atoms.