49 ideas
| 12667 | Metaphysics aims at the simplest explanation, without regard to testability [Ellis] |
| Full Idea: The methodology of metaphysics... is that of arguing to the simplest explanation, without regard to testability. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 1) | |
| A reaction: I love that! I'd be a bit cautious about 'simplest', since 'everything is the output of an ineffable God' is beautifully simple, and brings the whole discussion to a halt. I certainly think metaphysics goes deeper than testing. String Theory? |
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| Full Idea: Today we expect that anything worth calling a definition should imply a semantics. | |
| From: Ian Hacking (What is Logic? [1979], §10) | |
| A reaction: He compares this with Gentzen 1935, who was attempting purely syntactic definitions of the logical connectives. |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
| Full Idea: 'Dilution' (or 'Thinning') provides an essential contrast between deductive and inductive reasoning; for the introduction of new premises may spoil an inductive inference. | |
| From: Ian Hacking (What is Logic? [1979], §06.2) | |
| A reaction: That is, inductive logic (if there is such a thing) is clearly non-monotonic, whereas classical inductive logic is monotonic. |
| 13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
| Full Idea: If A |- B and B |- C, then A |- C. This generalises to: If Γ|-A,Θ and Γ,A |- Θ, then Γ |- Θ. Gentzen called this 'cut'. It is the transitivity of a deduction. | |
| From: Ian Hacking (What is Logic? [1979], §06.3) | |
| A reaction: I read the generalisation as 'If A can be either a premise or a conclusion, you can bypass it'. The first version is just transitivity (which by-passes the middle step). |
| 13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
| Full Idea: Only the cut rule can have a conclusion that is less complex than its premises. Hence when cut is not used, a derivation is quite literally constructive, building up from components. Any theorem obtained by cut can be obtained without it. | |
| From: Ian Hacking (What is Logic? [1979], §08) |
| 12666 | We can base logic on acceptability, and abandon the Fregean account by truth-preservation [Ellis] |
| Full Idea: In logic, acceptability conditions can replace truth conditions, ..and the only price one has to pay for this is that one has to abandon the implausible Fregean idea that logic is the theory of truth preservation. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 1) | |
| A reaction: This has always struck me as correct, given that if you assign T and F in a semantics, they don't have to mean 'true' and 'false', and that you can do very good logic with propositions which you think are entirely false. |
| 13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
| Full Idea: I don't believe English is by nature classical or intuitionistic etc. These are abstractions made by logicians. Logicians attend to numerous different objects that might be served by 'If...then', like material conditional, strict or relevant implication. | |
| From: Ian Hacking (What is Logic? [1979], §15) | |
| A reaction: The idea that they are 'abstractions' is close to my heart. Abstractions from what? Surely 'if...then' has a standard character when employed in normal conversation? |
| 13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
| Full Idea: First-order logic is the strongest complete compact theory with a Löwenheim-Skolem theorem. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
| Full Idea: Henkin proved that there is no first-order treatment of branching quantifiers, which do not seem to involve any idea that is fundamentally different from ordinary quantification. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: See Hacking for an example of branching quantifiers. Hacking is impressed by this as a real limitation of the first-order logic which he generally favours. |
| 13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
| Full Idea: Second-order logic has no chance of a completeness theorem unless one ventures into intensional entities and possible worlds. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
| Full Idea: My doctrine is that the peculiarity of the logical constants resides precisely in that given a certain pure notion of truth and consequence, all the desirable semantic properties of the constants are determined by their syntactic properties. | |
| From: Ian Hacking (What is Logic? [1979], §09) | |
| A reaction: He opposes this to Peacocke 1976, who claims that the logical connectives are essentially semantic in character, concerned with the preservation of truth. |
| 13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
| Full Idea: For some purposes the variables of first-order logic can be regarded as prepositions and place-holders that could in principle be dispensed with, say by a system of arrows indicating what places fall in the scope of which quantifier. | |
| From: Ian Hacking (What is Logic? [1979], §11) | |
| A reaction: I tend to think of variables as either pronouns, or as definite descriptions, or as temporary names, but not as prepositions. Must address this new idea... |
| 13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
| Full Idea: A Löwenheim-Skolem theorem holds for anything which, on my delineation, is a logic. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: I take this to be an unusually conservative view. Shapiro is the chap who can give you an alternative view of these things, or Boolos. |
| 12688 | Mathematics is the formal study of the categorical dimensions of things [Ellis] |
| Full Idea: I wish to explore the idea that mathematics is the formal study of the categorical dimensions of things. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 6) | |
| A reaction: Categorical dimensions are spatiotemporal relations and other non-causal properties. Ellis defends categorical properties as an aspect of science. The obvious connection seems to be with structuralism in mathematics. Shapiro is sympathetic. |
| 12683 | Objects and substances are a subcategory of the natural kinds of processes [Ellis] |
| Full Idea: The category of natural kinds of objects or substances should be regarded simply as a subcategory of the category of the natural kinds of processes. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: This is a new, and interesting, proposal from Ellis (which will be ignored by the philosophical community, as all new theories coming from elderly philosophers are ignored! Cf Idea 12652). A good knowledge of physics is behind Ellis's claim. |
| 12670 | A physical event is any change of distribution of energy [Ellis] |
| Full Idea: We may define a physical event as any change of distribution of energy in any of its forms. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: This seems to result in an awful lot of events. My own (new this morning) definition is: 'An event is a process which can be individuated in time'. Now you just have to work out what a 'process' is, but that's easier than understanding an 'event'. |
| 12673 | Physical properties are those relevant to how a physical system might act [Ellis] |
| Full Idea: We may define a physical property as one whose value is relevant, in some circumstances, to how a physical system is likely to act. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: Fair enough, but can we use the same 'word' property when we are discussing abstractions? Does 'The Enlightenment' have properties? Do very simple things have properties? Can 'red' act, if it isn't part of any physical system? |
| 12665 | I support categorical properties, although most people only want causal powers [Ellis] |
| Full Idea: I want to insist on the existence of a class of categorical properties distinct from causal powers. This is contentious, for there is a growing body of opinion that all properties are causal powers. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], Intro) | |
| A reaction: Alexander Bird makes a case against categorical properties. If what is meant is that 'being an electron' is the key property of an electron, then I disagree (quite strongly) with Ellis. Ellis says they are needed to explain causal powers. |
| 12682 | Essentialism needs categorical properties (spatiotemporal and numerical relations) and dispositions [Ellis] |
| Full Idea: Essentialist metaphysics seem to require that there be at least two kinds of properties in nature: dispositional properties (causal powers, capacities and propensities), and categorical ones (spatiotemporal and numerical relations). | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: At last someone tells us what a 'categorical' property is! Couldn't find it in Stanford! Bird and Molnar reject the categorical ones as true properties. If there are six cats, which cat has the property of being six? Which cat is 'three metres apart'? |
| 12684 | Spatial, temporal and numerical relations have causal roles, without being causal [Ellis] |
| Full Idea: Spatial, temporal and numerical relations can have various causal roles without themselves being instances of causal powers. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: He cites gaps, aggregates, orientations, approaching and receding, as examples of categorical properties which make a causal difference. I would have thought these could be incorporated in accounts of more basic causal powers. |
| 12672 | Properties and relations are discovered, so they can't be mere sets of individuals [Ellis] |
| Full Idea: To regard properties as sets of individuals, and relations as sets of ordered individuals, is to make a nonsense of the whole idea of discovering a new property or relationship. Sets are defined or constructed, not discovered. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: This bizarre view of properties (as sets) drives me crazy, until it dawns on you that they are just using the word 'property' in a different way, probably coextensively with 'predicate', in order to make the logic work. |
| 12676 | Causal powers can't rest on things which lack causal power [Ellis] |
| Full Idea: A causal power can never be dependent on anything that does not have any causal powers. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: Sounds right, though you worry when philosophers make such bold assertions about such extreme generalities. But see Idea 12667. This is, of course, the key argument for saying that causal powers are the bedrock of reality, and of explanation. |
| 23781 | Categoricals exist to influence powers. Such as structures, orientations and magnitudes [Ellis, by Williams,NE] |
| Full Idea: Ellis allows categoricals alongside powers, …to influence the sort of manifestations produced by powers. He lists structures, arrangements, distances, orientations, and magnitudes. | |
| From: report of Brian Ellis (The Metaphysics of Scientific Realism [2009]) by Neil E. Williams - The Powers Metaphysics 05.2 | |
| A reaction: I would have thought that all of these could be understood as manifestations of powers. The odd one out is distances, but then space and time are commonly overlooked in every attempt to produce a complete ontology. [also Molnar 2003:164]. |
| 12686 | Causal powers are a proper subset of the dispositional properties [Ellis] |
| Full Idea: The causal powers are just a proper subset of the dispositional properties. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 5) | |
| A reaction: Sounds wrong. Causal powers have a physical reality, while a disposition sounds as if it can wholly described by a counterfactual claim. It seems better to say that things have dispositions because they have powers. |
| 12132 | Indiscernibility is a necessary and sufficient condition for identity [Brody] |
| Full Idea: Enduring objects should be taken as fundamental in an ontology, and for all such objects indiscernibility is both a necessary and sufficient condition for identity. | |
| From: Baruch Brody (Identity and Essence [1980], 3) | |
| A reaction: Brody offers a substantial defence, but I don't find it plausible. Apart from Black's well known twin spheres example (Idea 10195), discernibility is relative to the powers of the observer. Two similar people in the mist aren't thereby identical. |
| 15834 | Brody bases sortal essentialism on properties required throughout something's existence [Brody, by Mackie,P] |
| Full Idea: Brody bases sortal essentialism on the notion of a property that an individual must possess throughout its existence if it possesses it at any time in its existence. | |
| From: report of Baruch Brody (Identity and Essence [1980]) by Penelope Mackie - How Things Might Have Been 7.1 | |
| A reaction: Brody tends to treat categories as properties, which I dislike. How do you assess 'must' here? A person may possess a mole throughout life without it being essential. |
| 12685 | Categorical properties depend only on the structures they represent [Ellis] |
| Full Idea: I would define categorical properties as those whose identities depend only on the kinds of structures they represent. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3 n8) | |
| A reaction: Aha. So categorical properties would be much more perspicaciously labelled as 'structural' properties. Why does philosophical terminology make it all more difficult than it needs to be? |
| 12140 | Modern emphasis is on properties had essentially; traditional emphasis is on sort-defining properties [Brody] |
| Full Idea: The modern emphasis has been on the connection between essential properties and the properties that an object must have essentially. But traditionally there is also the connection between essential properties and the sort of thing that it is. | |
| From: Baruch Brody (Identity and Essence [1980], 5.6) | |
| A reaction: These are the modal essence and the definitional essence. My view is that he has missed out a crucial third (Aristotelian) view, which is that essences are explanatory. This third view can subsume the other two. |
| 11895 | A sortal essence is a property which once possessed always possessed [Brody, by Mackie,P] |
| Full Idea: Brody bases sortal essentialism on the notion of a property that an individual must possess throughout its existence if it possesses it at any time in its existence. ...'Once an F, always an F'. ...Being a parrot is not a temporary occupation. | |
| From: report of Baruch Brody (Identity and Essence [1980]) by Penelope Mackie - How Things Might Have Been 7.1 | |
| A reaction: Hm. Would being less than fifty metres tall qualify as a sortal essence, for a giraffe or a uranium rod? If there is one thing an essential property should be, it is important. How do we assess importance? By explanatory power! Watch this space. |
| 12141 | Maybe essential properties are those which determine a natural kind? [Brody] |
| Full Idea: We can advance the thesis that all essential properties either determine a natural kind or are part of an essential property that does determine a natural kind. | |
| From: Baruch Brody (Identity and Essence [1980]) | |
| A reaction: A useful clear statement of the view. I am opposed to it, because I take it to be of the essence of Socrates that he is philosophical, but humans are not essentially philosophical, and philosophers are unlikely to be a natural kind. |
| 12679 | A real essence is a kind's distinctive properties [Ellis] |
| Full Idea: A distinctive set of intrinsic properties for a given kind is called a 'real essence'. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: Note that he thinks essence is a set of properties (rather than what gives rise to the properties), and that it is kinds (and not individuals) which have real essences, and that one role of the properties is to be 'distinctive' of the kind. Cf. Oderberg. |
| 12137 | De re essentialism standardly says all possible objects identical with a have a's essential properties [Brody] |
| Full Idea: To say that an object a has a property P essentially is to say that it has P, and in all of certain worlds (all possible, all in which something identical with it exists, ...) the object identical with it has P. This is the standard de re interpretation. | |
| From: Baruch Brody (Identity and Essence [1980], 5.4) | |
| A reaction: This view always has to be qualified by excluding trivially necessary properties, but that exclusion shows clearly that the notion of essential is more concerned with non-triviality than it is with necessity. |
| 12142 | Essentially, a has P, always had P, must have had P, and has never had a future without P [Brody] |
| Full Idea: 'a has property P essentially' means 'a has P, a always had P, there is no possible past in which P exists without P, and there is no moment of time at which a has had P and at which there is a possible future in which a exists without P' | |
| From: Baruch Brody (Identity and Essence [1980], 6) | |
| A reaction: This is Brody's own final account of essentialism. This is a carefully qualified form of the view that essential properties are, on the whole, the necessary properties, which view I take to be fundamentally mistaken. |
| 12143 | An object having a property essentially is equivalent to its having it necessarily [Brody] |
| Full Idea: An object having a property essentially is equivalent to its having it necessarily. | |
| From: Baruch Brody (Identity and Essence [1980], 6.1) | |
| A reaction: This strikes me as blatantly false. Personally I am toying with the very unorthodox view that essential properties are not at all necessary, and that something can retain its identity while changing its essential character. A philosopher with Alzheimers. |
| 12144 | Essentialism is justified if the essential properties of things explain their other properties [Brody] |
| Full Idea: The reasonableness of the essentialist hypothesis will be proportional to the extent that we can, as a result, use a's possession of P to explain a's other properties, ...and there is an inability to explain otherwise why a has P. | |
| From: Baruch Brody (Identity and Essence [1980], 6.3) | |
| A reaction: Brody as a rather liberal notion of properties. I would hope that we can do rather more than explain a's non-essential properties. If the non-essential properties were entailed by the essential ones, would they not then also be essential? |
| 12139 | Mereological essentialism says that every part that ensures the existence is essential [Brody] |
| Full Idea: Mereological essentialism (whose leading advocate is Chisholm) says that for every x and y, if x is ever part of y, then y is necessarily such that x is part of y at any time that y exists. | |
| From: Baruch Brody (Identity and Essence [1980], 5.6) | |
| A reaction: This sounds implausible, especially given the transitivity of parthood. Not only are the planks that constitute Theseus's Ship now essential to it, but all the parts of the planks, every last chip, are as well. |
| 12135 | Interrupted objects have two first moments of existence, which could be two beginnings [Brody] |
| Full Idea: If 'beginning of existence' meant 'first moment of existence after a period of nonexistence', then objects with interrupted existence have two beginnings of existence. | |
| From: Baruch Brody (Identity and Essence [1980], 4.1) | |
| A reaction: One might still maintain that the first beginning was essential to the object, since that is the event that defined it - and that would clarify the reason why we are supposed to think the origins are essential. I say the origin explains it. |
| 12130 | a and b share all properties; so they share being-identical-with-a; so a = b [Brody] |
| Full Idea: Suppose that a and b have all of their properties in common. a certainly has the property of-being-identical-with-a. So, by supposition, does b. Then a = b. | |
| From: Baruch Brody (Identity and Essence [1980], 1.2) | |
| A reaction: Brody defends this argument, and seems to think that it proves the identity of indiscernibles. As far as I can see it totally begs the question, since we can only assume that both have the property of being-identical-with-a if we have assumed a = b. |
| 12668 | Metaphysical necessity holds between things in the world and things they make true [Ellis] |
| Full Idea: Metaphysical necessitation is the relation that holds between things in the world and the things they make true. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 1) | |
| A reaction: Not sure about that. It implies that it is sentences that have necessity, and he confirms it by calling it 'a semantic relation'. So there are no necessities if there are no sentences? Not the Brian Ellis we know and love. |
| 12687 | Metaphysical necessities are those depending on the essential nature of things [Ellis] |
| Full Idea: A metaphysically necessary proposition is one that is true in virtue of the essential nature of things. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 6) | |
| A reaction: It take this to be what Kit Fine argues for, though it tracks back to Aristotle. I also take it to be correct, though one might ask whether there are any other metaphysical necessities, ones not depending on essences. |
| 12138 | Identity across possible worlds is prior to rigid designation [Brody] |
| Full Idea: Identity across possible worlds is prior to rigid designation. | |
| From: Baruch Brody (Identity and Essence [1980], 5.4) | |
| A reaction: An interesting view. We might stipulate that any possible Aristotle is 'our Aristotle', but you would still need criteria for deciding which possible Aristotle's would qualify. Long-frozen Aristotles, stupid Aristotles, alien Aristotle's, deformed... |
| 12669 | Science aims to explain things, not just describe them [Ellis] |
| Full Idea: The primary aim of science is to explain what happens, not just to describe it. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: This I take to be a good motto for scientific essentialism. Any scientist who is happy with anything less than explanation is a mere journeyman, a servant in the kitchens of the great house of science. |
| 12681 | There are natural kinds of processes [Ellis] |
| Full Idea: There are natural kinds of processes. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: Interesting. I am tempted by the view that processes are the most basic feature of reality, since I think of the mind as a process, and quantum reality seems more like processes than like objects. |
| 12680 | Natural kind structures go right down to the bottom level [Ellis] |
| Full Idea: Natural kind structures go all the way down to the most basic levels of existence. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: Even the bottom level? Is there anything to explain why the bottom level is a kind, given that all the higher kinds presumably have an explanation? |
| 12675 | Laws of nature are just descriptions of how things are disposed to behave [Ellis] |
| Full Idea: The laws of nature must be supposed to be just descriptions of the ways in which things are intrinsically disposed to behave: of how they would behave if they existed as closed and isolated systems. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 3) | |
| A reaction: I agree with this, and therefore take 'laws of nature' to be eliminable from any plausible ontology (which just contains the things and their behaviour). Ellis tends to defend laws, when he doesn't need to. |
| 12671 | I deny forces as entities that intervene in causation, but are not themselves causal [Ellis] |
| Full Idea: The classical conception of force is an entity that intervenes between a physical cause and its effect, but is not itself a physical cause. I see no reason to believe in forces of this kind. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: The difference of view between Leibniz and Newton is very illuminating on this one (coming this way soon!). Can you either have forces and drop causation, or have causation and drop forces? |
| 12674 | Energy is the key multi-valued property, vital to scientific realism [Ellis] |
| Full Idea: Perhaps the most important of all multi-valued properties is energy itself. I think a scientific realist must believe that energy exists. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: It's odd that the existence of the most basic thing in physics needs a credo from a certain sort of believer. I have been bothered by notion of 'energy' for fifty years, and am still none the wiser. I'm sure I could be scientific realist without it. |
| 12689 | Simultaneity can be temporal equidistance from the Big Bang [Ellis] |
| Full Idea: Cosmologists have a concept of objective simultaneity, which they take to mean something like 'temporally equidistant from the Big Bang'. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 6) | |
| A reaction: I find this very appealing, when faced with all the relativity theory that tells me there is no such thing as global simultaneity, a claim which I find deeply counterintuitive, but seems to have the science on its side. Bravo. |
| 12690 | The present is the collapse of the light wavefront from the Big Bang [Ellis] |
| Full Idea: The global wavefront that collapses when a light signal from the Big Bang is observed is what most plausibly defines the frontier between past and future. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 6) | |
| A reaction: I'm not sure I understand this, but it is clearly worth passing on. Of all the deep mysteries, the 'present' time may be the deepest. |