48 ideas
17016 | 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. |
18079 | 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. |
18082 | 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'. |
17011 | 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'. |
17028 | 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. |
17014 | 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. |
17546 | 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. |
17027 | 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. |
17022 | 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'. |
17021 | 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. |
17026 | 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). |
9312 | Consciousness is reductively explained either by how it represents, or how it is represented [Kriegel/Williford] |
Full Idea: The two main competitors for reductive theories of consciousness are the representational theory (conscious if it represents in the right way), and higher-order monitoring (conscious if it is represented in the right way). | |
From: U Kriegel / K Williford (Intro to 'Self-Representational Consciousness' [2006], Intro) | |
A reaction: Presumably there are also neuroscientists hunting for physical functions which might generate consciousness. The two mentioned here are rivals at one level of discourse. Both views may be simplistic, if complex teams of activities are involved. |
9313 | Experiences can be represented consciously or unconsciously, so representation won't explain consciousness [Kriegel/Williford] |
Full Idea: On the assumption that any environmental feature can be represented either consciously or unconsciously, it is unclear how the mere representation of such a feature can render the representing state conscious. | |
From: U Kriegel / K Williford (Intro to 'Self-Representational Consciousness' [2006], §1) | |
A reaction: The authors are rejecting simple representation as the key, in favour of a distinctive sort of self-representation. I'm inclined to think that consciousness results from multiple co-ordinated layers of representation etc., which has no simple account. |
9315 | Red tomato experiences are conscious if the state represents the tomato and itself [Kriegel/Williford] |
Full Idea: The self-representational theory of consciousness says that when one has a conscious experience as of a red tomato, one is in an internal state that represents both a red tomato and itself. | |
From: U Kriegel / K Williford (Intro to 'Self-Representational Consciousness' [2006], §1) | |
A reaction: This seems to be avoiding the concept of 'higher-order', and yet that seems the only way to describe it - thought steps outside of itself, generating a level of meta-thought. I think that's the way to go. Philosophy is about-fifth level. |
9316 | How is self-representation possible, does it produce a regress, and is experience like that? [Kriegel/Williford] |
Full Idea: The difficulties with a self-representational view of consciousness are how self-representation of mental states could be possible, whether it leads to an infinite regress, and whether it can capture the actual phenomenology of experience. | |
From: U Kriegel / K Williford (Intro to 'Self-Representational Consciousness' [2006], §3) | |
A reaction: [compressed] All of these objections strike me as persuasive, especially the first one. I'm not sure I know what self-representation is. Mirrors externally represent, and they can't represent themselves. Two mirrors together achieve something.. |
9314 | Unfortunately, higher-order representations could involve error [Kriegel/Williford] |
Full Idea: A problem for explaining consciousness by higher-order representations is that, like their first-order counterparts, they can misrepresent; there could be a subjective impression of being in a conscious state without actually being in any conscious state. | |
From: U Kriegel / K Williford (Intro to 'Self-Representational Consciousness' [2006], §1) | |
A reaction: It sounds plausible that this is a logical possibility, but how do you assess whether it is an actual or natural possibility? Are we saying that higher-order representations are judgments, which could be true or false? Hm. |
6421 | 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. |
13470 | 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]. |
17020 | 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. |
23012 | 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. |
8416 | Reductionists can't explain accidents, uninstantiated laws, probabilities, or the existence of any laws [Tooley] |
Full Idea: Reductionist accounts of causation cannot distinguish laws from accidental uniformities, cannot allow for basic uninstantiated laws, can't explain probabilistic laws, and cannot even demonstrate the existence of laws. | |
From: Michael Tooley (Causality: Reductionism versus Realism [1990], 2) | |
A reaction: I am tempted to say that this is so much the worse for the idea of laws. Extensive regularities only occur for a reason. Probabilities aren't laws. Hypothetical facts will cover uninstantiated laws. Laws are just patterns. |
8418 | Quantum physics suggests that the basic laws of nature are probabilistic [Tooley] |
Full Idea: Quantum physics seems to lend strong support to the idea that the basic laws of nature may well be probabilistic. | |
From: Michael Tooley (Causality: Reductionism versus Realism [1990], 3.2.1) | |
A reaction: Groan. Quantum physics should be outlawed from all philosophical discussions. The scientists don't understand it themselves. I'm certainly not going to build my worldview on it. I don't accept that these probabilities could count as 'laws'. |
17008 | 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. |
17010 | 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. |
17023 | 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). |
15866 | 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. |
15958 | 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. |
17017 | 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. |
17019 | 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'? |
20968 | 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). |
17018 | 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. |
17547 | 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? |
20966 | 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. |
20967 | 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. |
16708 | 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. |
13153 | 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. |
12724 | 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. |
13593 | 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. |
20969 | 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. |
17013 | 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. |
22915 | 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. |
22893 | 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. |
17012 | 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'. |
14012 | 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. |
22954 | 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. |
17015 | 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) |
17025 | 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) |
17024 | 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) |