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All the ideas for 'Logical Consequence', 'Intensions Revisited' and 'Principia Mathematica'

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55 ideas

1. Philosophy / D. Nature of Philosophy / 1. Philosophy
Philosophy must abstract from the senses [Newton]
     Full Idea: In philosophy abstraction from the senses is required.
     From: Isaac Newton (Principia Mathematica [1687], Def 8 Schol)
     A reaction: He particularly means 'natural philosophy' (i.e. science), but there is no real distinction in Newton's time, and I would say this remark is true of modern philosophy.
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall]
     Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion.
     From: JC Beall / G Restall (Logical Consequence [2005], Intro)
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
Quantified modal logic collapses if essence is withdrawn [Quine]
     Full Idea: The whole of quantified modal logic collapses if essence is withdrawn.
     From: Willard Quine (Intensions Revisited [1977], p.121)
     A reaction: Quine offers an interesting qualification to this crushing remark in Idea 13590. The point is that objects must retain their identity in modal contexts, as if I say 'John Kennedy might have been Richard Nixon'. What could that mean?
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall]
     Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought.
     From: JC Beall / G Restall (Logical Consequence [2005], 2)
     A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski.
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall]
     Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples.
     From: JC Beall / G Restall (Logical Consequence [2005], 3)
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall]
     Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists).
     From: JC Beall / G Restall (Logical Consequence [2005], 2)
     A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one.
5. Theory of Logic / B. Logical Consequence / 8. Material Implication
A step is a 'material consequence' if we need contents as well as form [Beall/Restall]
     Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form.
     From: JC Beall / G Restall (Logical Consequence [2005], 2)
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall]
     Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'.
     From: JC Beall / G Restall (Logical Consequence [2005], 4)
     A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are mathematical structures which interpret the non-logical primitives [Beall/Restall]
     Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language.
     From: JC Beall / G Restall (Logical Consequence [2005], 3)
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Newton developed a kinematic approach to geometry [Newton, by Kitcher]
     Full Idea: The reduction of the problems of tangents, normals, curvature, maxima and minima were effected by Newton's kinematic approach to geometry.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Philip Kitcher - The Nature of Mathematical Knowledge 10.1
     A reaction: This approach apparently contrasts with that of Leibniz.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits
Quantities and ratios which continually converge will eventually become equal [Newton]
     Full Idea: Quantities and the ratios of quantities, which in any finite time converge continually to equality, and, before the end of that time approach nearer to one another by any given difference become ultimately equal.
     From: Isaac Newton (Principia Mathematica [1687], Lemma 1), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.2
     A reaction: Kitcher observes that, although Newton relies on infinitesimals, this quotation expresses something close to the later idea of a 'limit'.
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall]
     Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives).
     From: JC Beall / G Restall (Logical Consequence [2005], 3)
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
I suspect that each particle of bodies has attractive or repelling forces [Newton]
     Full Idea: Many things lead me to a suspicion that all phenomena may depend on certain forces by which the particles of bodies, by causes not yet known, either are impelled toward one another and cohere in regular figures,or are repelled from one another and recede.
     From: Isaac Newton (Principia Mathematica [1687], Pref)
     A reaction: For Newton, forces are not just abstractions that are convenient for mathematics, but realities which I would say are best described as 'powers'.
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
Particles mutually attract, and cohere at short distances [Newton]
     Full Idea: The particles of bodies attract one another at very small distances and cohere when they become contiguous.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Gen Schol)
     A reaction: This is the sort of account of unity which has to be given in the corpuscular view of things, once substantial forms are given up. What is missing here is the structure of the thing. A lump of dirt is as unified as a cat in this story.
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
The place of a thing is the sum of the places of its parts [Newton]
     Full Idea: The place of a whole is the same as the sum of the places of the parts, and is therefore internal and in the whole body.
     From: Isaac Newton (Principia Mathematica [1687], Def 8 Schol)
     A reaction: Note that Newton is talking of the sums of places, and deriving them from the parts. This is the mereology of space.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Essences can make sense in a particular context or enquiry, as the most basic predicates [Quine]
     Full Idea: The notion of essence makes sense in context. Relative to a particular enquiry, some predicates may play a more basic role than others, or may apply more fixedly; and these may be treated as essential.
     From: Willard Quine (Intensions Revisited [1977], p.121)
     A reaction: Quine has got a bad press on essentialism, and on modal logic, but I take this point seriously. If you give something a fixed identity by means of essence in some context, you can then go ahead and apply possible world reasoning in that context.
10. Modality / A. Necessity / 11. Denial of Necessity
Necessity is relative to context; it is what is assumed in an inquiry [Quine]
     Full Idea: The very notion of necessity makes sense to me only relative to context. Typically it is applied to what is assumed in an inquiry, as against what has yet to transpire.
     From: Willard Quine (Intensions Revisited [1977], p.121)
     A reaction: Lots of things are assumed by an inquiry without an assumption that they must be true. Quine is the greatest opponent of necessity in all of philosophy. Asserting necessities, though, is too much fun to give up. It would ruin philosophy.
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds are a way to dramatise essentialism, and yet they presuppose essentialism [Quine]
     Full Idea: Talk of possible worlds is a graphic way of waging the essentialist philosophy, but it is only that; it is not an explication. Essence is needed to identify an object from one possible world to another.
     From: Willard Quine (Intensions Revisited [1977], p.118)
     A reaction: He makes the proposal sound circular, but I take a commitment to essences to be prior to talk of possible worlds. Possible worlds are a tool for clarifying modalities, not for clarifying essential identities.
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
A rigid designator (for all possible worlds) picks out an object by its essential traits [Quine]
     Full Idea: A rigid designator differs from others in that it picks out its object by essential traits. It designates the object in all possible worlds in which it exists.
     From: Willard Quine (Intensions Revisited [1977], p.118)
     A reaction: This states the point more clearly than Kripke ever does, and I presume it is right. Thus when we say that we wish 'our' Hubert Humphrey had won the election, we can allow that his victory elation would change him a bit. Kripke is right.
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
Beliefs can be ascribed to machines [Quine]
     Full Idea: Beliefs have been ascribed to machines, in support of a mechanistic philosophy, and I share this attitude.
     From: Willard Quine (Intensions Revisited [1977], p.123)
     A reaction: [He cites Raymond Nelson] One suspects that this is Quine's latent behaviourism speaking. It strikes me as a crass misuse of 'belief' to ascribe it to a simple machine like a thermostat.
14. Science / B. Scientific Theories / 6. Theory Holism
If you changed one of Newton's concepts you would destroy his whole system [Heisenberg on Newton]
     Full Idea: The connection between the different concept in [Newton's] system is so close that one could generally not change any one of the concepts without destroying the whole system
     From: comment on Isaac Newton (Principia Mathematica [1687]) by Werner Heisenberg - Physics and Philosophy 06
     A reaction: This holistic situation would seem to count against Newton's system, rather than for it. A good system should depend on nature, not on other parts of the system. Compare changing a rule of chess.
14. Science / C. Induction / 1. Induction
Science deduces propositions from phenomena, and generalises them by induction [Newton]
     Full Idea: In experimental philosophy, propositions are deduced from the phenomena and are made general by induction.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Gen Schol)
     A reaction: Sounds easy, but generalising by induction requires all sorts of assumptions about the stability of natural kinds. Since the kinds are only arrived at by induction, it is not easy to give a proper account here.
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
We should admit only enough causes to explain a phenomenon, and no more [Newton]
     Full Idea: No more causes of natural things should be admitted than are both true and sufficient to explain the phenomena. …For nature does nothing in vain, …and nature is simple and does not indulge in the luxury of superfluous causes.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Rule 1)
     A reaction: This emphasises that Ockham's Razor is a rule for physical explanation, and not just one for abstract theories. This is something like Van Fraassen's 'empirical adequacy'.
Natural effects of the same kind should be assumed to have the same causes [Newton]
     Full Idea: The causes assigned to natural effects of the same kind must be, so far as possible, the same. For example, the cause of respiration in man and beast.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Rule 2)
     A reaction: It is impossible to rule out identical effects from differing causes, but explanation gets much more exciting (because wide-ranging) if Newton's rule is assumed.
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
From the phenomena, I can't deduce the reason for the properties of gravity [Newton]
     Full Idea: I have not as yet been able to deduce from the phenomena the reason for the properties of gravity.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Gen Schol)
     A reaction: I take it that giving the reasons for the properties of gravity would be an essentialist explanation. I am struck by the fact that the recent discovery of the Higgs Boson appears to give us a reason why things have mass (i.e. what causes mass).
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 / 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.
26. Natural Theory / C. Causation / 1. Causation
Newtonian causation is changes of motion resulting from collisions [Newton, by Baron/Miller]
     Full Idea: In the Newtonian mechanistic theory of causation, ….something causes a result when it brings about a change of motion. …Causation is a matter of things bumping into one another.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Baron,S/Miller,K - Intro to the Philosophy of Time 6.2.1
     A reaction: This seems to need impenetrability and elasticity as primitives (which is partly what Leibniz's monads are meant to explain). The authors observe that much causation is the result of existences and qualities, rather than motions.
26. Natural Theory / D. Laws of Nature / 6. Laws as Numerical
You have discovered that elliptical orbits result just from gravitation and planetary movement [Newton, by Leibniz]
     Full Idea: You have made the astonishing discovery that Kepler's ellipses result simply from the conception of attraction or gravitation and passage in a planet.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Gottfried Leibniz - Letter to Newton 1693.03.07
     A reaction: I quote this to show that Newton made 'an astonishing discovery' of a connection in nature, and did not merely produce an equation which described a pattern of behaviour. The simple equation is the proof of the connection.
We have given up substantial forms, and now aim for mathematical laws [Newton]
     Full Idea: The moderns - rejecting substantial forms and occult qualities - have undertaken to reduce the phenomena of nature to mathematical laws.
     From: Isaac Newton (Principia Mathematica [1687], Preface)
     A reaction: This is the simplest statement of the apparent anti-Aristotelian revolution in the seventeenth century.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
I am not saying gravity is essential to bodies [Newton]
     Full Idea: I am by no means asserting that gravity is essential to bodies.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Rule 3)
     A reaction: Notice that in Idea 17009 he does not rule out gravity being essential to bodies. This is Newton's intellectual modesty (for which he is not famous).
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Newton reclassified vertical motion as violent, and unconstrained horizontal motion as natural [Newton, by Harré]
     Full Idea: Following Kepler, Newton assumed a law of universal gravitation, thus reclassifying free fall as a violent motion and, with his First Law, fixing horizontal motion in the absence of constraints as natural
     From: report of Isaac Newton (Principia Mathematica [1687]) by Rom Harré - Laws of Nature 1
     A reaction: This is in opposition to the Aristotelian view, where the downward motion of physical objects is their natural motion.
27. Natural Reality / A. Classical Physics / 1. Mechanics / b. Laws of motion
Inertia rejects the Aristotelian idea of things having natural states, to which they return [Newton, by Alexander,P]
     Full Idea: Newton's principle of inertia implies a rejection of the Aristotelian idea of natural states to which things naturally return.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Peter Alexander - Ideas, Qualities and Corpuscles 02.3
     A reaction: I think we can safely say that Aristotle was wrong about this. Aristotle made too much (such as the gravity acting on a thing) intrinsic to the bodies, when the whole context must be seen.
1: Bodies rest, or move in straight lines, unless acted on by forces [Newton]
     Full Idea: Law 1: Every body perseveres in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by forces impressed.
     From: Isaac Newton (Principia Mathematica [1687], Axioms)
     A reaction: This is the new concept of inertia, which revolutionises the picture. Motion itself, which was a profound puzzle for the Greeks, ceases to be a problem by being axiomatised. It is now acceleration which is the the problem.
Newton's Third Law implies the conservation of momentum [Newton, by Papineau]
     Full Idea: Newton's Third Law implies the conservation of momentum, because 'action and reaction' are always equal.
     From: report of Isaac Newton (Principia Mathematica [1687]) by David Papineau - Thinking about Consciousness App 3
     A reaction: That is, the Third Law implies the First Law (which is the Law of Momentum).
2: Change of motion is proportional to the force [Newton]
     Full Idea: Law 2: A change in motion is proportional to the motive force impressed and takes place along the straight line in which that force is impressed.
     From: Isaac Newton (Principia Mathematica [1687], Axioms)
     A reaction: This gives the equation 'force = mass x acceleration', where the mass is the constant needed for the equation of proportion. Effectively mass is just the value of a proportion.
3: All actions of bodies have an equal and opposite reaction [Newton]
     Full Idea: Law 3: To any action there is always an opposite and equal reaction; in other words, the action of two bodies upon each other are always equal and always opposite in direction.
     From: Isaac Newton (Principia Mathematica [1687], Axioms)
     A reaction: Is this still true if one body is dented by the impact and the other one isn't? What counts as a 'body'?
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
Newton's idea of force acting over a long distance was very strange [Heisenberg on Newton]
     Full Idea: Newton introduced a very new and strange hypothesis by assuming a force that acted over a long distance.
     From: comment on Isaac Newton (Principia Mathematica [1687]) by Werner Heisenberg - Physics and Philosophy 06
     A reaction: Why would a force that acted over a short distance be any less mysterious?
Newton introduced forces other than by contact [Newton, by Papineau]
     Full Idea: Newton allowed forces other than impact. All the earlier proponents of 'mechanical philosophy' took it as given that all physical action is by contact. ...He thought of 'impressed force' - disembodied entities acting from outside a body.
     From: report of Isaac Newton (Principia Mathematica [1687]) by David Papineau - Thinking about Consciousness App 3
     A reaction: This is 'action at a distance', which was as bewildering then as quantum theory is now. Newton had a divinity to impose laws of nature from the outside. In some ways we have moved back to the old view, with the actions of bosons and fields.
Newton's laws cover the effects of forces, but not their causes [Newton, by Papineau]
     Full Idea: Newton has a general law about the effects of his forces, ...but there is no corresponding general principle about the causes of such forces.
     From: report of Isaac Newton (Principia Mathematica [1687]) by David Papineau - Thinking about Consciousness App 3
     A reaction: I'm not sure that Einstein gives a cause of gravity either. This seems to be part of the scientific 'instrumentalist' view of nature, which is incredibly useful but very superficial.
Newton's forces were accused of being the scholastics' real qualities [Pasnau on Newton]
     Full Idea: Newton's reliance on the notion of force was widely criticised as marking in effect a return to real qualities.
     From: comment on Isaac Newton (Principia Mathematica [1687]) by Robert Pasnau - Metaphysical Themes 1274-1671 19.7
     A reaction: The objection is to forces that are separate from the bodies they act on. This is one of the reasons why modern metaphysics needs the concept of an intrinsic disposition or power, placing the forces in the stuff.
I am studying the quantities and mathematics of forces, not their species or qualities [Newton]
     Full Idea: I consider in this treatise not the species of forces and their physical qualities, but their quantities and mathematical proportions.
     From: Isaac Newton (Principia Mathematica [1687], 1.1.11 Sch)
     A reaction: Note that Newton is not denying that one might contemplate the species and qualities of forces, as I think Leibniz tried to do, thought he didn't cast any detailed light on them. It is the gap between science and metaphysics.
The aim is to discover forces from motions, and use forces to demonstrate other phenomena [Newton]
     Full Idea: The basic problem of philosophy seems to be to discover the forces of nature from the phenomena of motions and then to demonstrate the other phenomena from these forces.
     From: Isaac Newton (Principia Mathematica [1687], Pref 1st ed), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 4
     A reaction: This fits in with the description-of-regularity approach to laws which Newton had acquired from Galileo, rather than the essentialist attitude to forces of Leibniz, though Newton has smatterings of essentialism.
27. Natural Reality / A. Classical Physics / 1. Mechanics / d. Gravity
Newton showed that falling to earth and orbiting the sun are essentially the same [Newton, by Ellis]
     Full Idea: Newton showed that the apparently different kinds of processes of falling towards the earth and orbiting the sun are essentially the same.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Brian Ellis - Scientific Essentialism 3.08
     A reaction: I quote this to illustrate Newton's permanent achievement in science, in the face of a tendency to say that he was 'outmoded' by the advent of General Relativity. Newton wasn't interestingly wrong. He was very very right.
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / c. Conservation of energy
Early Newtonians could not formulate conservation of energy, having no concept of potential energy [Newton, by Papineau]
     Full Idea: A barrier to the formulation of an energy conservation principle by early Newtonians was their lack of a notion of potential energy.
     From: report of Isaac Newton (Principia Mathematica [1687]) by David Papineau - Thinking about Consciousness App 3 n5
     A reaction: Interestingly, the notions of potentiality and actuality were central to Aristotle, but Newtonians had just rejected all of that.
27. Natural Reality / C. Space / 4. Substantival Space
Absolute space is independent, homogeneous and immovable [Newton]
     Full Idea: Absolute space, of its own nature without reference to anything external, always remains homogeneous and immovable.
     From: Isaac Newton (Principia Mathematica [1687], Def 8 Schol)
     A reaction: This would have to be a stipulation, rather than an assertion of fact, since whether space is 'immovable' is either incoherent or unknowable.
27. Natural Reality / D. Time / 1. Nature of Time / a. Absolute time
Newton needs intervals of time, to define velocity and acceleration [Newton, by Le Poidevin]
     Full Idea: Both Newton's First and Second Laws of motion make implicit reference to equal intervals of time. For a body is moving with constant velocity if it covers the same distance in a series of equal intervals (and similarly with acceleration).
     From: report of Isaac Newton (Principia Mathematica [1687]) by Robin Le Poidevin - Travels in Four Dimensions 01 'Time'
     A reaction: [Le Poidevin spells out the acceleration point] You can see why he needs time to be real, if measured chunks of it figure in his laws.
Newton thought his laws of motion needed absolute time [Newton, by Bardon]
     Full Idea: Newton's reason for embracing absolute space, time and motion was that he thought that universal laws of motions were describable only in such terms. Because actual motions are irregular, the time of universal laws of motion cannot depend on them.
     From: report of Isaac Newton (Principia Mathematica [1687]) by Adrian Bardon - Brief History of the Philosophy of Time 3 'Replacing'
     A reaction: I'm not sure of the Einsteinian account of the laws of motion.
Time exists independently, and flows uniformly [Newton]
     Full Idea: Absolute, true, and mathematical time, in and of itself and of its own nature, without reference to anything external, flows uniformly and by another name is called duration.
     From: Isaac Newton (Principia Mathematica [1687], Def 8 Schol)
     A reaction: This invites the notorious question of, if time flows uniformly, how fast time flows. Maybe we should bite the bullet and say 'one second per second', or maybe we should say 'this fact is beyond our powers of comprehension'.
Absolute time, from its own nature, flows equably, without relation to anything external [Newton]
     Full Idea: Absolute, true, and mathematical time, of itself, and from its own nature, flows equably, without relation to anything external.
     From: Isaac Newton (Principia Mathematica [1687], I:Schol after defs), quoted by Craig Bourne - A Future for Presentism 5.1
     A reaction: I agree totally with this, and I don't care what any modern relativity theorists say. It think Shoemaker's argument gives wonderful support to Newton.
27. Natural Reality / D. Time / 2. Passage of Time / g. Time's arrow
Newtonian mechanics does not distinguish negative from positive values of time [Newton, by Coveney/Highfield]
     Full Idea: In Newton's laws of motion time is squared, so a negative value gives the same result as a positive value, which means Newtonian mechanics cannot distinguish between the two directions of time.
     From: report of Isaac Newton (Principia Mathematica [1687]) by P Coveney / R Highfield - The Arrow of Time 2 'anatomy'
     A reaction: Maybe Newton just forgot to mention that negative values were excluded. (Or was he unaware of the sequence of negative integers?). Too late now - he's done it.
27. Natural Reality / D. Time / 3. Parts of Time / d. Measuring time
If there is no uniform motion, we cannot exactly measure time [Newton]
     Full Idea: It is possible that there is no uniform motion by which time may have an exact measure. All motions can be accelerated and retarded, but the flow of absolute time cannot be changed.
     From: Isaac Newton (Principia Mathematica [1687], Def 8 Schol)
28. God / A. Divine Nature / 3. Divine Perfections
If a perfect being does not rule the cosmos, it is not God [Newton]
     Full Idea: A being, however perfect, without dominion is not the Lord God.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Gen Schol)
28. God / B. Proving God / 3. Proofs of Evidence / b. Teleological Proof
The elegance of the solar system requires a powerful intellect as designer [Newton]
     Full Idea: This most elegant system of the sun, planets, and comets could not have arisen without the design and dominion of an intelligent and powerful being.
     From: Isaac Newton (Principia Mathematica [1687], Bk 3 Gen Schol)