41 ideas
12027 | There must be a plausible epistemological theory alongside any metaphysical theory [Forbes,G] |
Full Idea: No metaphysical account which renders it impossible to give a plausible epistemological theory is to be countenanced. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 9.1) | |
A reaction: It is hard to object to this principle, though we certainly don't want to go verificationist, and thus rule out speculations about metaphysics which are beyond any possible knowledge. Some have tried to prove that something must exist (e.g. Jacquette). |
10365 | We might use 'facta' to refer to the truth-makers for facts [Mellor, by Schaffer,J] |
Full Idea: Mellor offers a distinction between 'facts' and 'facta' (the latter being the truth-makers for facts). | |
From: report of D.H. Mellor (The Facts of Causation [1995]) by Jonathan Schaffer - The Metaphysics of Causation 1.1 | |
A reaction: The idea is that 'facta' can do the work in causation, because 'facts' are not part of the world. This seems a very helpful terminology, which should be encouraged, since 'fact' is plainly ambiguous in current usage. |
12005 | The symbol 'ι' forms definite descriptions; (ιx)F(x) says 'the x which is such that F(x)' [Forbes,G] |
Full Idea: We use the symbol 'ι' (Greek 'iota') to form definite descriptions, reading (ιx)F(x) as 'the x which is such that F(x)', or simply as 'the F'. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.1) | |
A reaction: Compare the lambda operator in modal logic, which picks out predicates from similar formulae. |
12010 | Is the meaning of 'and' given by its truth table, or by its introduction and elimination rules? [Forbes,G] |
Full Idea: The typical semantic account of validity for propositional connectives like 'and' presupposes that meaning is given by truth-tables. On the natural deduction view, the meaning of 'and' is given by its introduction and elimination rules. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.4) |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points. | |
From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13 | |
A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry. |
12023 | Vagueness problems arise from applying sharp semantics to vague languages [Forbes,G] |
Full Idea: It is very plausible that the sorites paradoxes arose from the application of a semantic apparatus appropriate only for sharp predicates to languages containing vague predicates (rather than from deficiency of meaning, or from incoherence). | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.3) | |
A reaction: Sounds wrong. Of course, logic has been designed for sharp predicates, and natural languages are awash with vagueness. But the problems of vagueness bothered lawyers long before logicians like Russell began to worry about it. |
8568 | A property is merely a constituent of laws of nature; temperature is just part of thermodynamics [Mellor] |
Full Idea: Being a constituent of probabilistic laws of nature is all there is to being a property. There is no more to temperature than the thermodynamics and other laws they occur in. | |
From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
A reaction: How could thermodynamics be worked out without a prior concept of temperature? I think it is at least plausible to deny that there are any 'laws' of nature. But even Quine can't deny that some things are too hot to touch. |
8564 | There is obviously a possible predicate for every property [Mellor] |
Full Idea: To every property there obviously corresponds a possible predicate applying to all and only those particulars with that property. | |
From: D.H. Mellor (Properties and Predicates [1991], 'Intro') | |
A reaction: This doesn't strike me as at all obvious. If nature dictates the properties, there may be vastly more than any human language could cope with. It is daft to say that a property can only exist if humanity can come up with a predicate for it. |
8566 | We need universals for causation and laws of nature; the latter give them their identity [Mellor] |
Full Idea: I take the main reason for believing in contingent universals to be the roles they play in causation and in laws of nature, and those laws are what I take to give those universals their identity. | |
From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
A reaction: He agrees with Armstrong. Sounds a bit circular - laws are built on universals, and universals are identified by laws. It resembles a functionalist account of mental events. I think it is wrong. A different account of laws will be needed... |
8565 | If properties were just the meanings of predicates, they couldn't give predicates their meaning [Mellor] |
Full Idea: One reason for denying that properties just are the meanings of our predicates is that, if they were, they could not give our predicates their meanings. | |
From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
A reaction: Neither way round sounds quite right to me. Predicate nominalism is wrong, but what is meant by a property 'giving' a predicate its meaning? It doesn't seem to allow room for error in our attempts to name the properties. |
12017 | In all instances of identity, there must be some facts to ensure the identity [Forbes,G] |
Full Idea: For each instance of identity or failure of identity, there must be facts in virtue of which that instance obtains. ..Enough has been said to lend this doctrine some plausibility. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.5) | |
A reaction: Penelope Mackie picks this out from Forbes as a key principle. It sounds to be in danger of circularity, unless the 'facts' can be cited without referring to, or implicitly making use of, identities - which seems unlikely. |
12024 | If we combined two clocks, it seems that two clocks may have become one clock. [Forbes,G] |
Full Idea: If we imagine a possible world in which two clocks in a room make one clock from half the parts of each, the judgement 'these two actual clocks could have been a single clock' does not seem wholly false. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.4) | |
A reaction: You would, of course, have sufficient parts left over to make a second clock, so they look like a destroyed clock, so I don't think I find Forbes's intuition on this one very persuasive. |
11885 | Only individual essences will ground identities across worlds in other properties [Forbes,G, by Mackie,P] |
Full Idea: Forbes argues that, unless we posit individual essences, we cannot guarantee that identities across possible worlds will be appropriately grounded in other properties. | |
From: report of Graeme Forbes (The Metaphysics of Modality [1985]) by Penelope Mackie - How Things Might Have Been 2.4 | |
A reaction: There is a confrontation between Wiggins, who says identity is primitive, and Forbes, who says identity must be grounded in other properties. I think I side with Forbes. |
12014 | An individual essence is a set of essential properties which only that object can have [Forbes,G] |
Full Idea: An individual essence of an object x is a set of properties I which satisfies the following conditions: i. every property P in I is an essential property of x; ii. it is not possible that some object y distinct from x has every member of I. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: I am coming to the view that stable natural kinds (like electrons or gold) do not have individual essences, but complex kinds (like tigers or tables) do. The view is based on the idea that explanatory power is what individuates an essence. |
12015 | Non-trivial individual essence is properties other than de dicto, or universal, or relational [Forbes,G] |
Full Idea: A non-trivial individual essence is properties other than a) those following from a de dicto truth, b) properties of existence and self-identity (or their cognates), c) properties derived from necessities in some other category. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: [I have compressed Forbes] Rather than adding all these qualificational clauses to our concept, we could just tighten up on the notion of a property, saying it is something which is causally efficacious, and hence explanatory. |
12013 | Essential properties depend on a category, and perhaps also on particular facts [Forbes,G] |
Full Idea: The essential properties of a thing will typically depend upon what category of thing it is, and perhaps also on some more particular facts about the thing itself. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: I see no way of dispensing with the second requirement, in the cases of complex entities like animals. If all samples are the same, then of course we can define a sample's essence through its kind, but not if samples differ in any way. |
13804 | A property is essential iff the object would not exist if it lacked that property [Forbes,G] |
Full Idea: A property P is an essential property of an object x iff x could not exist and lack P, that is, as they say, iff x has P at every world at which x exists. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 1) | |
A reaction: This immediately places the existence of x outside the normal range of its properties, so presumably 'existence is not a predicate', but that dictum may be doubted. As it stands this definition will include trivial and vacuous properties. |
13805 | Properties are trivially essential if they are not grounded in a thing's specific nature [Forbes,G] |
Full Idea: Essential properties may be trivial or nontrivial. It is characteristic of P's being trivially essential to x that x's possession of P is not grounded in the specific nature of x. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 2) | |
A reaction: This is where my objection to the modal view of essence arises. How is he going to explain 'grounded' and 'specific nature' without supplying an entirely different account of essence? |
12012 | Essential properties are those without which an object could not exist [Forbes,G] |
Full Idea: An essential property of an object x is a property without possessing which x could not exist. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: This is certainly open to question. See Joan Kung's account of Aristotle on essence. I am necessarily more than eight years old (now), and couldn't exist without that property, but is the property part of my essence? |
13808 | A relation is essential to two items if it holds in every world where they exist [Forbes,G] |
Full Idea: A relation R is essential to x and y (in that order) iff Rxy holds at every world where x and y both exist. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 2) | |
A reaction: I find this bizarre. Not only does this seem to me to have nothing whatever to do with essence, but also the relation might hold even though it is a purely contingent matter. All rabbits are a reasonable distance from the local star. Essence of rabbit? |
13806 | Trivially essential properties are existence, self-identity, and de dicto necessities [Forbes,G] |
Full Idea: The main groups of trivially essential properties are (a) existence, self-identity, or their consequences in S5; and (b) properties possessed in virtue of some de dicto necessary truth. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 2) | |
A reaction: He adds 'extraneously essential' properties, which also strike me as being trivial, involving relations. 'Is such that 2+2=4' or 'is such that something exists' might be necessary, but they don't, I would say, have anything to do with essence. |
13807 | A property is 'extraneously essential' if it is had only because of the properties of other objects [Forbes,G] |
Full Idea: P is 'extraneously essential' to x iff it is possessed by x at any world w only in virtue of the possession at w of certain properties by other objects. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 2) | |
A reaction: I would say that these are the sorts of properties which have nothing to do with being essential, even if they are deemed to be necessary. |
12022 | Same parts does not ensure same artefact, if those parts could constitute a different artefact [Forbes,G] |
Full Idea: Sameness of parts is not sufficient for identity of artefacts at a world, since the very same parts may turn up at different times as the parts of artefacts with different designs and functions. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.2) | |
A reaction: Thus the Ship of Theseus could be dismantled and turned into a barn (as happened with the 'Mayflower'). They could then be reconstituted as the ship, which would then have two beginnings (as Chris Hughes has pointed out). |
12025 | Artefacts have fuzzy essences [Forbes,G] |
Full Idea: Artefacts can be ascribed fuzzy essences. ...We might say that it is essential to an artefact to have 'most' of its parts. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.6) | |
A reaction: I think I prefer to accept the idea that essences are unstable things, in all cases. For all we know, electrons might subtly change their general character, or cease to be uniform, tomorrow. Essences explain, and what needs explaining changes. |
13809 | One might be essentialist about the original bronze from which a statue was made [Forbes,G] |
Full Idea: In the case of artefacts, there is an essentialism about original matter; for instance, it would be said of any particular bronze statue that it could not have been cast from a totally different quantity of bronze. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 3) | |
A reaction: Forbes isn't endorsing this, and it doesn't sound convincing. He quotes the thought 'I wish I had made this pot from a different piece of clay'. We might corrupt a statue by switching bronze, but I don't think the sculptor could do so. |
12020 | An individual might change their sex in a world, but couldn't have differed in sex at origin [Forbes,G] |
Full Idea: In the time of a single world, the same individual can undergo a change of sex, but it is less clear that an individual of one sex could have been, from the outset, an individual of another. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 6.5) | |
A reaction: I don't find this support for essentiality of origin very persuasive. I struggle with these ideas. Given my sex yesterday, then presumably I couldn't have had a different sex yesterday. Given that pigs can fly, pigs can fly. What am I missing? |
11888 | Identities must hold because of other facts, which must be instrinsic [Forbes,G, by Mackie,P] |
Full Idea: Forbes has two principles of identity, which we can call the No Bare Identities Principle (identities hold in virtue of other facts), and the No Extrinsic Determination Principle (that only intrinsic facts of a thing establish identity). | |
From: report of Graeme Forbes (The Metaphysics of Modality [1985], 127-8) by Penelope Mackie - How Things Might Have Been 2.7 | |
A reaction: The job of the philosopher is to prise apart the real identities of things from the way in which we conceive of identities. I take these principles to apply to real identities, not conceptual identities. |
12003 | De re modal formulae, unlike de dicto, are sensitive to transworld identities [Forbes,G] |
Full Idea: The difference between de re and de dicto formulae is a difference between formulae which are, and formulae which are not, sensitive to the identities of objects at various worlds. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 3.1) |
12028 | De re necessity is a form of conceptual necessity, just as de dicto necessity is [Forbes,G] |
Full Idea: De re necessity does not differ from de dicto necessity in respect of how it arises: it is still a form of conceptual necessity. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 9.4) | |
A reaction: [Forbes proceeds to argue for this claim] Forbes defends a form of essentialism, but takes the necessity to arise from a posteriori truths because of the a priori involvement of other concepts (rather as Kripke argues). |
13810 | The source of de dicto necessity is not concepts, but the actual properties of the thing [Forbes,G] |
Full Idea: It is widely held that the source of de dicto necessity is in concepts, ..but I deny this... even with simple de dicto necessities, the source of the necessity is to be found in the properties to which the predicates of the de dicto truth refer. | |
From: Graeme Forbes (In Defense of Absolute Essentialism [1986], 3) | |
A reaction: It is normal nowadays to say this about de re necessities, but this is more unusual. |
12008 | Unlike places and times, we cannot separate possible worlds from what is true at them [Forbes,G] |
Full Idea: There is no means by which we might distinguish a possible world from what is true at it. ...Whereas our ability to separate a place, or a time, from its occupier is crucial to realism about places and times, as is a distance relation. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.2) | |
A reaction: He is objecting to Lewis's modal realism. I'm not fully convinced. It depends whether we are discussing real ontology or conceptual space. In the latter I see no difference between times and possible worlds. In ontology, a 'time' is weird. |
12009 | The problem with possible worlds realism is epistemological; we can't know properties of possible objects [Forbes,G] |
Full Idea: The main objection to realism about worlds is from epistemology. Knowledge of properties of objects requires experience of these objects, which must be within the range of our sensory faculties, but only concrete actual objects achieve that. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.2) | |
A reaction: This pinpoints my dislike of the whole possible worlds framework, ontologically speaking. I seem to be an actualist. I take possibilities to be inferences to the best explanation from the powers we know of in the actual world. We experience potentiality. |
12007 | Possible worlds are points of logical space, rather like other times than our own [Forbes,G] |
Full Idea: Someone impressed by the parallel between tense and modal operators ...might suggest that just as we can speak of places and times forming their own manifolds or spaces, so we can say that worlds are the points of logical space. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.2) | |
A reaction: I particularly like the notion of worlds being "points of logical space", and am inclined to remove it from this context and embrace it as the correct way to understand possible worlds. We must understand logical or conceptual space. |
12011 | Transworld identity concerns the limits of possibility for ordinary things [Forbes,G] |
Full Idea: An elucidation of transworld identity can be regarded as an elucidation of the boundaries of possibility for ordinary things. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: I presume that if we don't search for some such criterion, we just have to face the possibility that Aristotle could have been a poached egg in some possible world. To know the bounds of possibility, study the powers of actual objects. |
12016 | The problem of transworld identity can be solved by individual essences [Forbes,G] |
Full Idea: The motivation for investigating individual essences should be obvious, since if every object has such an essence, the problem of elucidating transworld identity can be solved. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: It is important that, if necessary, the identities be 'individual', and not just generic, by sortal, or natural kind. We want to reason about (and explain) truths at the fine-grained level of the individual, not just at the broad level of generalisation. |
12004 | Counterpart theory is not good at handling the logic of identity [Forbes,G] |
Full Idea: The outstanding technical objection to counterpart-theoretic semantics concerns its handling of the logic of identity. In quantified S5 (the orthodox semantics) a = b → □(a = b) is valid, but 'a' must not attach to two objects. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 3.5) |
12021 | Haecceitism attributes to each individual a primitive identity or thisness [Forbes,G] |
Full Idea: Haecceitism attributes to each individual a primitive identity or thisness, as opposed to the sort of essentialism that gives non-trivial conditions sufficient for transworld identity. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 6.6) | |
A reaction: 'Haecceitism' is the doctrine that things have primitive identity. A 'haecceity' is a postulated property which actually does the job. The key point of the view is that whatever it is is 'primitive', and not complex, or analysable. I don't believe it. |
12029 | We believe in thisnesses, because we reject bizarre possibilities as not being about that individual [Forbes,G] |
Full Idea: The natural response to an unreasonable hypothesis of possibility for an object x, that in such a state of affairs it would not be x which satisfies the conditions, is evidence that we do possess concepts of thisness for individuals. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 9.4) | |
A reaction: We may have a 'concept' of thisness, but we needn't be committed to the 'existence' of a thisness. There is a fairly universal intuition that cessation of existence of an entity when it starts to change can be a very vague matter. |
4785 | Causal statements relate facts (which are whatever true propositions express) [Mellor, by Psillos] |
Full Idea: Mellor argues that causal statements relate facts, where facts may be seen as whatever true propositions express. | |
From: report of D.H. Mellor (The Facts of Causation [1995]) by Stathis Psillos - Causation and Explanation §2.6 | |
A reaction: Choose between 'facts', 'objects', 'conserved quantities, 'events' (the usual one) or 'processes'. I rather like processes (Salmon) as they are a better prospect as the building blocks of an ontology. |
8567 | Singular causation requires causes to raise the physical probability of their effects [Mellor] |
Full Idea: Singular causation entails physical probabilities or chances. ...Causal laws require causes to raise their effects' chances, as when fires have a greater chance of occurring when explosions do. | |
From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
A reaction: It seems fairly obvious that a probability can be increased without actually causing something. Just after a harmless explosion is a good moment for arsonists, especially if Mellor will be the investigating officer. |
8408 | Probabilistic causation says C is a cause of E if it increases the chances of E occurring [Mellor, by Tooley] |
Full Idea: The basic idea of probabilistic causation is that a sufficient condition of C's being a cause of E is that C and E are actual, individual events, and the objective chance of E's occurring is greater given the occurrence of C than it would be without C. | |
From: report of D.H. Mellor (The Facts of Causation [1995]) by Michael Tooley - Causation and Supervenience 5.3 | |
A reaction: Mellor has to include objective 'chances' in his ontology to support his theory. As it stands this looks like a weak theory, since the event might not occur despite C happening, and some less likely event might turn out to be the actual cause. |