19 ideas
| 9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
| Full Idea: Logic is part of a normative theory of thinking, not a substitute for thinking. | |
| From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13) | |
| A reaction: There is some sort of logicians' dream, going back to Leibniz, of a reasoning engine, which accepts propositions and outputs inferences. I agree with this idea. People who excel at logic are often, it seems to me, modest at philosophy. |
| 20457 | Zeno assumes collecting an infinity of things makes an infinite thing [Rovelli] |
| Full Idea: One possible answer is that Zeno is wrong because it is not true that by accumulating an infinite number of things one ends up with an infinite thing. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 01) | |
| A reaction: I do love it when deep and complex ideas are expressed with perfect simplicity. As long as the simple version is correct. |
| 20468 | Quantum mechanics deals with processes, rather than with things [Rovelli] |
| Full Idea: Quantum mechanics teaches us not to think about the world in terms of 'things' which are in this or that state, but in terms of 'processes' instead. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
| 20467 | Quantum mechanics describes the world entirely as events [Rovelli] |
| Full Idea: The world of quantum mechanics is not a world of objects: it is a world of events. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
| A reaction: I presume a philosopher is allowed to ask what an 'event' is. Since, as Rovelli tells it, time is eliminated from the picture, events seem to be unanalysable primitives. |
| 9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |
| Full Idea: Vagueness in respect of membership is consistency with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of a concept. | |
| From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5) | |
| A reaction: I find this view of sets much more appealing than the one that identifies a set with its members. The empty set is less of a problem, as well as non-existents. Logicians prefer the extensional view because it is tidy. |
| 19355 | The soul doesn't understand many of its own actions, if perceptions are confused and desires buried [Leibniz] |
| Full Idea: The soul does many things without knowing how it does them - when it does them by means of confused perceptions and unconscious inclinations or appetites. | |
| From: Gottfried Leibniz (On Note L to Bayle's 'Rorarius' [1705], [L]) | |
| A reaction: This increasingly strikes me as a wonderful and important insight for its time. He's really paid attention to his own mind, and given up the simplistic view that derives from Descartes. Are birds conscious? Yes or no! Silly. |
| 19350 | We should say that body is mechanism and soul is immaterial, asserting their independence [Leibniz] |
| Full Idea: I think we should keep both sides: we should be more Democritean and make all actions of bodies mechanical and independent of souls, and we should also be more than Platonic and hold that all actions of souls are immaterial and independent of mechanism. | |
| From: Gottfried Leibniz (On Note L to Bayle's 'Rorarius' [1705], [C]) | |
| A reaction: This is about as dualist as it is possible to get. It certainly looks as if many of Leibniz's doctrines are rebellions against Spinoza (in this case his 'dual aspect monism'). I take Leibniz to be utterly but heroically wrong. |
| 19356 | Minds unconsciously count vibration beats in music, and enjoy it when they coincide [Leibniz] |
| Full Idea: In music, the soul counts the beats of the vibrating object which makes the sound, and when these beats regularly coincide at short intervals, it finds them pleasing. Thus it counts without knowing it. | |
| From: Gottfried Leibniz (On Note L to Bayle's 'Rorarius' [1705], [L]) | |
| A reaction: Only a mathematician would see music this way! He is defending his account of the unconscious mind. The proposal that we unconsciously count sounds highly implausible. He needs to recognise the patterns that ground mathematics. |
| 20469 | There are probably no infinities, and 'infinite' names what we do not yet know [Rovelli] |
| Full Idea: 'Infinite', ultimately, is the name that we give to what we do not yet know. Nature appears to be telling us that there is nothing truly infinite. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 11) |
| 20461 | The basic ideas of fields and particles are merged in quantum mechanics [Rovelli] |
| Full Idea: The notions of fields and particles, separated by Faraday and Maxwell, end up merging in quantum mechanics. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
| A reaction: This sounds to me just like Anaximander's 'apeiron' - the unlimited [Rovelli agrees! p.168]. Anaximander predicted the wall which enquiry would hit, but we now have more detail. |
| 20462 | Because it is quantised, a field behaves like a set of packets of energy [Rovelli] |
| Full Idea: Since the energy of the electromagnetic field can take on only certain values, the field behaves like a set of packets of energy. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
| 20463 | There are about fifteen particles fields, plus a few force fields [Rovelli] |
| Full Idea: There are about fifteen fields, whose quanta are elementary particles (electrons, quarks, muons, neutrinos, Higgs, and little else), plus a few fields similar to the electromagnetic one, which describe forces at a nuclear scale, with quanta like photons. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
| A reaction: According to Rovelli, this sentence describes the essence of physical reality. |
| 20464 | The world consists of quantum fields, with elementary events happening in spacetime [Rovelli] |
| Full Idea: The world is not made up of fields and particles, but of a single type of entity: the quantum field. There are no longer particles which move in space with the passage of time, but quantum fields whose elementary events happen in spacetime. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
| A reaction: If you are not a scientist, there is (I find) a strong tendency to read and digest stuff like this, and then forget it the next day, because it so far from our experience. Folk like me have to develop two parallel views of the nature of reality. |
| 20459 | Electrons only exist when they interact, and their being is their combination of quantum leaps [Rovelli] |
| Full Idea: Electrons don't always exist. They exist when they interact. They materialize when they collide with something. The quantum leap from one orbit to another constitutes their way of being real. An electron is a combination of leaps between interactions. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
| A reaction: If a philosopher with an Aristotelian interest in the nature of matter wants to grasp the modern view, the electron looks like the thing to focus on. You can feel Rovelli battling here to find formulations that might satisfy a philosopher. |
| 20460 | Electrons are not waves, because their collisions are at a point, and not spread out [Rovelli] |
| Full Idea: Schrödinger's wave is a bad image for an electron, because when a particle collides with something else, it is always at a point: it is never spread out in space like a wave. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04 note) | |
| A reaction: And yet there is the diffusion in the two-slit experiment, which Thomas Young discovered for light. I must take Rovelli's word for this. |
| 20466 | Quantum Theory describes events and possible interactions - not how things are [Rovelli] |
| Full Idea: Quantum Theory does not describe things as they are: it describes how things occur and interact with each other. It doesn't describe where there is a particle but how it shows itself to others. The world of existence is reduced to possible interactions. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
| A reaction: Fans of 'process philosophy' should like this, though he is not denying that there may be facts about how things are - it is just that this is not mentioned in the theory. There is not much point in philosophers yearning to know the reality. |
| 20465 | Nature has three aspects: granularity, indeterminacy, and relations [Rovelli] |
| Full Idea: I think that quantum mechanics has revealed three aspects of the nature of things: granularity, indeterminacy, and the relational structure of the world. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
| 20458 | The world is just particles plus fields; space is the gravitational field [Rovelli] |
| Full Idea: The world is made up of particles + fields, and nothing else; there is no need to add space as an extra ingredient. Newton's space is the gravitational field. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 03) | |
| A reaction: I get the impression that particles are just bumps or waves in the fields [yes! Rovelli p.110], which would mean there are fields and nothing else. And no one seems to know what a field is. |
| 20470 | Only heat distinguishes past from future [Rovelli] |
| Full Idea: It is always heat and only heat that distinguishes the past from the future. | |
| From: Carlo Rovelli (Reality is Not What it Seems [2014], 12) | |
| A reaction: I can remember the past but not the future - so can that fact be reduced to facts about heat? |