43 ideas
| 12249 | 'Animal' is a genus and 'rational' is a specific difference [Oderberg] |
| Full Idea: The standard classification holds that 'animal' is a genus and 'rational' is a specific difference. | |
| From: David S. Oderberg (Real Essentialism [2007], 3.5) | |
| A reaction: My understanding of 'difference' would take it down to the level of the individual, so the question is - which did Aristotle believe in. Not all commentators agree with Oderberg, and Wedin thinks the individual substance is paramount. |
| 12242 | Definition distinguishes one kind from another, and individuation picks out members of the kind [Oderberg] |
| Full Idea: To define something just means to set forth its limits in such a way that one can distinguish it from all other things of a different kind. To distinguish it from all other things of the same kind belongs to the theory of 'individuation'. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.4) | |
| A reaction: I take Aristotle to have included individuation as part of his understanding of definition. Are tigers a kind, or are fierce tigers a kind, and is my tiger one-of-a-kind? |
| 12238 | The Aristotelian view is that numbers depend on (and are abstracted from) other things [Oderberg] |
| Full Idea: The Aristotelian account of numbers is that their existence depends on the existence of things that are not numbers, ..since numbers are abstractions from the existence of things. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.2) | |
| A reaction: This is the deeply unfashionable view to which I am attached. The problem is the status of transfinite, complex etc numbers. They look like fictions to me. |
| 12254 | Being is substantial/accidental, complete/incomplete, necessary/contingent, possible, relative, intrinsic.. [Oderberg] |
| Full Idea: Being is heterogeneous: there is substantial being, accidental being, complete being, incomplete being, necessary being, contingent being, possible being, absolute being, relative being, intrinsic being, extrinsic being, and so on. | |
| From: David S. Oderberg (Real Essentialism [2007], 5.3) | |
| A reaction: Dependent being? Oderberg is giving the modern scholastic view. Personally I take 'being' to be univocal, even if it can be qualified in all sorts of ways. I don't believe we actually have any grasp at all of different ways to exist. |
| 12253 | If tropes are in space and time, in what sense are they abstract? [Oderberg] |
| Full Idea: If tropes are in space and time, in what sense are they abstract? | |
| From: David S. Oderberg (Real Essentialism [2007], 4.5) | |
| A reaction: I take this to be a conclusive objection to claims for any such thing to be abstract. See, for example, Dummett's claim that the Equator is an abstract object. |
| 12256 | We need to distinguish the essential from the non-essential powers [Oderberg] |
| Full Idea: We need a theory of essence to help us distinguish between the powers that do and do not belong to the essence of a thing. | |
| From: David S. Oderberg (Real Essentialism [2007], 6.3) | |
| A reaction: I take this to be a very good reason for searching for the essence of things, though the need to distinguish does not guarantee that there really is something to distinguish. Maybe powers just come and go. A power is essential in you but not in me? |
| 12252 | Empiricists gave up 'substance', as unknowable substratum, or reducible to a bundle [Oderberg] |
| Full Idea: The demise of 'substance' was wholly due to mistaken notions, mainly from the empiricists, by which it was conceived either as an unknowable featureless substratum, or as dispensable in favour of some or other bundle theory. | |
| From: David S. Oderberg (Real Essentialism [2007], 4.4) | |
| A reaction: There seems to be a view that the notion of substance is essential to explaining how we understand the world. I am inclined to think that if we accept the notion of essence we can totally dispense with the notion of substance. |
| 12241 | Essences are real, about being, knowable, definable and classifiable [Oderberg, by PG] |
| Full Idea: Real essences are objectively real, they concern being, they are knowable, they are definable, and they are classifiable. | |
| From: report of David S. Oderberg (Real Essentialism [2007], 1.4) by PG - Db (ideas) | |
| A reaction: This is a lovely summary (spread over two pages) of what essentialism is all about. It might be added that they are about unity and identity. The fact that they are intrinsically classifiable seems to mislead some people into a confused view. |
| 12244 | Nominalism is consistent with individual but not with universal essences [Oderberg] |
| Full Idea: Nominalism is consistent with belief in individual essences, but real essentialism postulates essences as universals (quiddities). Nominalists are nearly always empiricists, though the converse may not be the case. | |
| From: David S. Oderberg (Real Essentialism [2007], 2.1) | |
| A reaction: This is where I part company with Oderberg. I want to argue that the nominalist/individualist view is more in tune with what Aristotle believed (though he spotted a dilemma here). Only individual essences explain individual behaviour. |
| 12240 | Essentialism is the main account of the unity of objects [Oderberg] |
| Full Idea: Real essentialism, more than any other ontological theory, stresses and seeks to explain the unity of objects. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.3) | |
| A reaction: A key piece in the jigsaw I am beginning to assemble. If explanation is the aim, and essence the key to explanation, then explaining unity is the part of it that connects with other metaphysics, about identity and so on. 'Units' breed numbers. |
| 12247 | Essence is not explanatory but constitutive [Oderberg] |
| Full Idea: Essence is not reducible to explanatory relations, ...and fundamentally the role of essence is not explanatory but constitutive. | |
| From: David S. Oderberg (Real Essentialism [2007], 3.1) | |
| A reaction: Effectively, this asserts essence as part of 'pure' metaphysics, but I like impure metaphysics, as the best explanation of the things we can know. Hence we can speculate about constitution only by means of explanation. Constitution is active. |
| 12258 | Properties are not part of an essence, but they flow from it [Oderberg] |
| Full Idea: A substance is constituted by its essence, and properties are a species of accident. No property of a thing is part of a thing's essence, though properties flow from the essence. | |
| From: David S. Oderberg (Real Essentialism [2007], 7.2) | |
| A reaction: I'm not sure I understand this. How can you know of something which has no properties? I'm wondering if the whole notion of a 'property' should be eliminated from good metaphysics. |
| 12257 | Could we replace essence with collections of powers? [Oderberg] |
| Full Idea: Why not do away with talk of essences and replace it with talk of powers pure and simple, or reduce essences to collections of powers? But then what unites the powers, and could a power be lost, and is there entailment between the powers? | |
| From: David S. Oderberg (Real Essentialism [2007], 6.3) | |
| A reaction: [He cites Bennett and Hacker 2003 for this view] The point would seem to be that in addition to the powers, there are also identity and unity and kind-membership to be explained. Oderberg says the powers flow from the essence. |
| 12236 | Leibniz's Law is an essentialist truth [Oderberg] |
| Full Idea: Leibniz's Law is an essentialist truth. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.1) | |
| A reaction: That is, if two things must have identical properties because they are the same thing, this is because those properties are essential to the thing. Otherwise two things could be the same, even though one of them lacked a non-identifying property. |
| 12250 | Bodies have act and potency, the latter explaining new kinds of existence [Oderberg] |
| Full Idea: The fundamental thesis of real essentialism is that every finite material body has a twofold composition, being a compound of act and potency. ...Reality can take on new kinds of existence because there is a principle of potentiality inherent in reality. | |
| From: David S. Oderberg (Real Essentialism [2007], 4.1) | |
| A reaction: I take from this remark that the 'powers' discussed by Molnar and other scientific essentialists is roughly the same as 'potentiality' identified by Aristotle. |
| 12234 | Realism about possible worlds is circular, since it needs a criterion of 'possible' [Oderberg] |
| Full Idea: Any realist theory of possible worlds will be circular in its attempt to illuminate modality, for there has to be some criterion of what counts as a possible world. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.1) | |
| A reaction: Seems right. At the very least, if we are going to rule out contradictory worlds as impossible (and is there a more obvious criterion?), we already need to understand 'impossible' in order to state that rule. |
| 12235 | Necessity of identity seems trivial, because it leaves out the real essence [Oderberg] |
| Full Idea: The necessity of identity carries the appearance of triviality, because it is the eviscerated contemporary essentialist form of a foundational real essentialist truth to the effect that every object has its own nature. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.1) | |
| A reaction: I like this. Writers like Mackie and Forbes have to put the 'trivial' aspects of essence to one side, without ever seeing why there is such a problem. Real substantial essences have necessity of identity as a side-effect. |
| 12237 | Rigid designation has at least three essentialist presuppositions [Oderberg] |
| Full Idea: The rigid designator approach to essentialism has essentialist assumptions. ..The necessity of identity is built into the very conception of a rigid designator,..and Leibniz's Law is presupposed...and necessity of origin presupposes sufficiency of origin. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.1) | |
| A reaction: [compressed. He cites Salmon 1981:196 for the last point] This sounds right. You feel happy to 'rigidly designate' something precisely because you think there is something definite and stable which can be designated. |
| 7506 | God made man in his own image [Anon (Tor)] |
| Full Idea: And God said, let us make man in our image, after our likeness. | |
| From: Anon (Tor) (01: Book of Genesis [c.750 BCE], 1.26) | |
| A reaction: Since we are obviously not identical in every way with God, we can presumably choose in which respects we think of ourselves as being like Him. Reason, understanding, beauty, goodness, consciousness? A troublesome verse, challenged by Darwin. |
| 12245 | Essence is the source of a thing's characteristic behaviour [Oderberg] |
| Full Idea: In the traditional terminology, function follows essence. Essence just is the principle from which flows the characteristic behaviour of a thing. | |
| From: David S. Oderberg (Real Essentialism [2007], 2.1) | |
| A reaction: Hence essence must be identified if the behaviour is to be explained, and a successful identification of essence is the terminus of our explanations. But the essences must go down to the micro-level. Explain non-characteristic behaviour? |
| 12246 | What makes Parmenidean reality a One rather than a Many? [Oderberg] |
| Full Idea: Even if there were no multiplicity in unity - only a Parmenidean 'block' - still the question would arise as to what gave the amorphous lump its unity; by virtue of what would it be one rather than many? | |
| From: David S. Oderberg (Real Essentialism [2007], 3.1) | |
| A reaction: Which is prior, division or unification? If it was divided, he would ask what divided it. One of them must be primitive, so why not unity? If one big Unity is primitive, why could not lots of unities be primitive? Etc. |
| 16782 | The names of all the types of creature were given forever by Adam [Anon (Tor)] |
| Full Idea: Whatsoever Adam called any living creature, the same is its name. And Adam called all the beasts by their names, and all the fowls of the air, and all the cattle of the field. | |
| From: Anon (Tor) (01: Book of Genesis [c.750 BCE], 02:20) |
| 12239 | The real essentialist is not merely a scientist [Oderberg] |
| Full Idea: It is incorrect to hold that the job of the real essentialist just is the job of the scientist. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.3) | |
| A reaction: Presumably scientific essentialism, while being firmly a branch of metaphysics, is meant to clarify the activities of science, and thereby be of some practical use. You can't beat knowing what it is you are trying to do. |
| 12243 | The reductionism found in scientific essentialism is mistaken [Oderberg] |
| Full Idea: The reductionism found in scientific essentialism is mistaken. | |
| From: David S. Oderberg (Real Essentialism [2007], 1.4) | |
| A reaction: Oderberg's point is that essence doesn't just occur at the bottom of the hierarchy of kinds, but can exist on a macro-level, and need not be a concealed structure, as we see in the essence of a pile of stones. |
| 20624 | Work degrades into heat, but not vice versa [Close] |
| Full Idea: William Thomson, Lord Kelvin, declared (in 1865) the second law of thermodynamics: mechanical work inevitably tends to degrade into heat, but not vice versa. | |
| From: Frank Close (Theories of Everything [2017], 3 'Perpetual') | |
| A reaction: The basis of entropy, which makes time an essential part of physics. Might this be the single most important fact about the physical world? |
| 20623 | First Law: energy can change form, but is conserved overall [Close] |
| Full Idea: The first law of thermodynamics : energy can be changed from one form to another, but is always conserved overall. | |
| From: Frank Close (Theories of Everything [2017], 3 'Perpetual') | |
| A reaction: So we have no idea what energy is, but we know it's conserved. (Daniel Bernoulli showed the greater the mean energy, the higher the temperature. James Joule showed the quantitative equivalence of heat and work p.26-7) |
| 20625 | Third Law: total order and minimum entropy only occurs at absolute zero [Close] |
| Full Idea: The third law of thermodynamics says that a hypothetical state of total order and minimum entropy can be attained only at the absolute zero temperature, minus 273 degrees Celsius. | |
| From: Frank Close (Theories of Everything [2017], 3 'Arrow') | |
| A reaction: If temperature is energetic movement of atoms (or whatever), then obviously zero movement is the coldest it can get. So is absolute zero an energy state, or an absence of energy? I have no idea what 'total order' means. |
| 20622 | All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close] |
| Full Idea: There is no absolute state of rest; only relative motions are unambiguous. Contrast this with acceleration, however, which has the same magnitude in all inertial frames. | |
| From: Frank Close (Theories of Everything [2017], 3 'Newton's') | |
| A reaction: It seems important to remember this, before we start trumpeting about the whole of physics being relative. ....But see Idea 20634! |
| 20628 | The electric and magnetic are tightly linked, and viewed according to your own motion [Close] |
| Full Idea: Electric and magnetic phenomena are profoundly intertwined; what you interpret as electric or magnetic thus depends on your own motion. | |
| From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
| A reaction: This sounds like an earlier version of special relativity. |
| 20635 | The general relativity equations relate curvature in space-time to density of energy-momentum [Close] |
| Full Idea: The essence of general relativity relates 'curvature in space-time' on one side of the equation to the 'density of momentum and energy' on the other. ...In full, Einstein required ten equations of this type. | |
| From: Frank Close (Theories of Everything [2017], 5 'Gravity') | |
| A reaction: Momentum involves mass, and energy is equivalent to mass (e=mc^2). |
| 20627 | Electric fields have four basic laws (two by Gauss, one by Ampère, one by Faraday) [Close] |
| Full Idea: Four basic laws of electric and magnetic fields: Gauss's Law (about the flux produced by a field), Gauss's law of magnets (there can be no monopoles), Ampère's Law (fields on surfaces), and Farday's Law (accelerated magnets produce fields). | |
| From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
| A reaction: [Highly compressed, for an overview. Close explains them] |
| 20630 | Light isn't just emitted in quanta called photons - light is photons [Close] |
| Full Idea: Planck had assumed that light is emitted in quanta called photons. Einstein went further - light is photons. | |
| From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
| A reaction: The point is that light travels as entities which are photons, rather than the emissions being quantized packets of some other stuff. |
| 20637 | In general relativity the energy and momentum of photons subjects them to gravity [Close] |
| Full Idea: In Einstein's general theory, gravity acts also on energy and momentum, not simply on mass. For example, massless photons of light feel the gravitational attraction of the Sun and can be deflected. | |
| From: Frank Close (Theories of Everything [2017], 5 'Planck') | |
| A reaction: Ah, a puzzle solved. How come massless photons are bent by gravity? |
| 20629 | Electro-magnetic waves travel at light speed - so light is electromagnetism! [Close] |
| Full Idea: Faradays' measurements predicted the speed of electro-magnetic waves, which happened to be the speed of light, so Maxwell made an inspired leap: light is an electromagnetic wave! | |
| From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
| A reaction: Put that way, it doesn't sound like an 'inspired' leap, because travelling at exactly the same speed seems a pretty good indication that they are the same sort of thing. (But I'm not denying that Maxwell was a special guy!) |
| 20632 | In QED, electro-magnetism exists in quantum states, emitting and absorbing electrons [Close] |
| Full Idea: Dirac created quantum electrodynamics (QED): the universal electro-magnetic field can exist in discreet states of energy (with photons appearing and disappearing by energy excitations. This combined classical ideas, quantum theory and special relativity. | |
| From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
| A reaction: Close says this is the theory of everything in atomic structure, but not in nuclei (which needs QCD and QFD). So if there are lots of other 'fields' (e.g. gravitational, weak, strong, Higgs), how do they all fit together? Do they talk to one another? |
| 20642 | Photon exchange drives the electro-magnetic force [Close] |
| Full Idea: The exchange of photons drives the electro-magnetic force. | |
| From: Frank Close (Theories of Everything [2017], 6 'Superstrings') | |
| A reaction: So light, which we just think of as what is visible, is a mere side-effect of the engine room of nature - the core mechanism of the whole electro-magnetic field. |
| 20639 | Quantum fields contain continual rapid creation and disappearance [Close] |
| Full Idea: Quantum field theory implies that the vacuum of space is filled with particles and antiparticles which bubble in and out of existence on faster and faster timescales over shorter and shorter distances. | |
| From: Frank Close (Theories of Everything [2017], 6 'Intro') | |
| A reaction: Ponder this sentence until you head aches. Existence, but not as we know it, Jim. Close says calculations in QED about the electron confirm this. |
| 20631 | Dirac showed how electrons conform to special relativity [Close] |
| Full Idea: In 1928 Paul Dirac discovered the quantum equation that describes the electron and conforms to the requirements special relativity theory. | |
| From: Frank Close (Theories of Everything [2017], 3 'Light!') | |
| A reaction: This sounds like a major step in the unification of physics. Quantum theory and General relativity remain irreconcilable. |
| 20641 | Electrons get their mass by interaction with the Higgs field [Close] |
| Full Idea: The electron gets its mass by interaction with the ubiquitous Higgs field. | |
| From: Frank Close (Theories of Everything [2017], 6 'Hierarchy') | |
| A reaction: I thought I understood mass until I read this. Is it just wrong to say the mass of a table is the 'amount of stuff' in it? |
| 20626 | Modern theories of matter are grounded in heat, work and energy [Close] |
| Full Idea: The link between temperature, heat, work and energy is at the root of our historical ability to construct theories of matter, such as Newton's dynamics, while ignoring, and indeed being ignorant of - atomic dimensions. | |
| From: Frank Close (Theories of Everything [2017], 3 'Arrow') | |
| A reaction: That is, presumably, that even when you fill in the atoms, and the standard model of physics, these aspects of matter do the main explaiining (of the behaviour, rather than of the structure). |
| 20633 | The Higgs field is an electroweak plasma - but we don't know what stuff it consists of [Close] |
| Full Idea: In 2012 it was confirmed that we are immersed in an electroweak plasma - the Higgs field. We curently have no knowledge of what this stuff might consist of. | |
| From: Frank Close (Theories of Everything [2017], 4 'Higgs') | |
| A reaction: The second sentence has my full attention. So we don't understand a field properly until we understand the 'stuff' it is made of? So what are all the familiar fields made of? Tell me more! |
| 20640 | Space-time is indeterminate foam over short distances [Close] |
| Full Idea: At very short distances, space-time itself becomes some indeterminate foam. | |
| From: Frank Close (Theories of Everything [2017], 6 'Intro') | |
| A reaction: [see Close for a bit more detail of this weird idea] |
| 4013 | And God saw the light, that it was good [Anon (Tor)] |
| Full Idea: And God saw the light, that it was good. | |
| From: Anon (Tor) (01: Book of Genesis [c.750 BCE], 01.04) | |
| A reaction: The text seems to suggest that God did not decide that it was good, but that it conformed to a standard of goodness. |