Combining Philosophers

All the ideas for R Martin / J Barresi, Graeme Forbes and Keith Hossack

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65 ideas

1. Philosophy / E. Nature of Metaphysics / 2. Possibility of Metaphysics
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).
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL
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.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice is a non-logical principle of set-theory [Hossack]
     Full Idea: The Axiom of Choice seems better treated as a non-logical principle of set-theory.
     From: Keith Hossack (Plurals and Complexes [2000], 4 n8)
     A reaction: This reinforces the idea that set theory is not part of logic (and so pure logicism had better not depend on set theory).
The Axiom of Choice guarantees a one-one correspondence from sets to ordinals [Hossack]
     Full Idea: We cannot explicitly define one-one correspondence from the sets to the ordinals (because there is no explicit well-ordering of R). Nevertheless, the Axiom of Choice guarantees that a one-one correspondence does exist, even if we cannot define it.
     From: Keith Hossack (Plurals and Complexes [2000], 10)
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets
Predicativism says only predicated sets exist [Hossack]
     Full Idea: Predicativists doubt the existence of sets with no predicative definition.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 02.3)
     A reaction: This would imply that sets which encounter paradoxes when they try to be predicative do not therefore exist. Surely you can have a set of random objects which don't fall under a single predicate?
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The iterative conception has to appropriate Replacement, to justify the ordinals [Hossack]
     Full Idea: The iterative conception justifies Power Set, but cannot justify a satisfactory theory of von Neumann ordinals, so ZFC appropriates Replacement from NBG set theory.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 09.9)
     A reaction: The modern approach to axioms, where we want to prove something so we just add an axiom that does the job.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of Size justifies Replacement, but then has to appropriate Power Set [Hossack]
     Full Idea: The limitation of size conception of sets justifies the axiom of Replacement, but cannot justify Power Set, so NBG set theory appropriates the Power Set axiom from ZFC.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 09.9)
     A reaction: Which suggests that the Power Set axiom is not as indispensable as it at first appears to be.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Maybe we reduce sets to ordinals, rather than the other way round [Hossack]
     Full Idea: We might reduce sets to ordinal numbers, thereby reversing the standard set-theoretical reduction of ordinals to sets.
     From: Keith Hossack (Plurals and Complexes [2000], 10)
     A reaction: He has demonstrated that there are as many ordinals as there are sets.
4. Formal Logic / G. Formal Mereology / 3. Axioms of Mereology
Extensional mereology needs two definitions and two axioms [Hossack]
     Full Idea: Extensional mereology defs: 'distinct' things have no parts in common; a 'fusion' has some things all of which are parts, with no further parts. Axioms: (transitivity) a part of a part is part of the whole; (sums) any things have a unique fusion.
     From: Keith Hossack (Plurals and Complexes [2000], 5)
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and
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)
The connective 'and' can have an order-sensitive meaning, as 'and then' [Hossack]
     Full Idea: The sentence connective 'and' also has an order-sensitive meaning, when it means something like 'and then'.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 10.4)
     A reaction: This is support the idea that orders are a feature of reality, just as much as possible concatenation. Relational predicates, he says, refer to series rather than to individuals. Nice point.
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
'Before' and 'after' are not two relations, but one relation with two orders [Hossack]
     Full Idea: The reason the two predicates 'before' and 'after' are needed is not to express different relations, but to indicate its order. Since there can be difference of order without difference of relation, the nature of relations is not the source of order.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 10.3)
     A reaction: This point is to refute Russell's 1903 claim that order arises from the nature of relations. Hossack claims that it is ordered series which are basic. I'm inclined to agree with him.
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
Plural definite descriptions pick out the largest class of things that fit the description [Hossack]
     Full Idea: If we extend the power of language with plural definite descriptions, these would pick out the largest class of things that fit the description.
     From: Keith Hossack (Plurals and Complexes [2000], 3)
5. Theory of Logic / G. Quantification / 6. Plural Quantification
Plural reference will refer to complex facts without postulating complex things [Hossack]
     Full Idea: It may be that plural reference gives atomism the resources to state complex facts without needing to refer to complex things.
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: This seems the most interesting metaphysical implication of the possibility of plural quantification.
Plural reference is just an abbreviation when properties are distributive, but not otherwise [Hossack]
     Full Idea: If all properties are distributive, plural reference is just a handy abbreviation to avoid repetition (as in 'A and B are hungry', to avoid 'A is hungry and B is hungry'), but not all properties are distributive (as in 'some people surround a table').
     From: Keith Hossack (Plurals and Complexes [2000], 2)
     A reaction: The characteristic examples to support plural quantification involve collective activity and relations, which might be weeded out of our basic ontology, thus leaving singular quantification as sufficient.
A plural comprehension principle says there are some things one of which meets some condition [Hossack]
     Full Idea: Singular comprehension principles have a bad reputation, but the plural comprehension principle says that given a condition on individuals, there are some things such that something is one of them iff it meets the condition.
     From: Keith Hossack (Plurals and Complexes [2000], 4)
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / d. Russell's paradox
Plural language can discuss without inconsistency things that are not members of themselves [Hossack]
     Full Idea: In a plural language we can discuss without fear of inconsistency the things that are not members of themselves.
     From: Keith Hossack (Plurals and Complexes [2000], 4)
     A reaction: [see Hossack for details]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
The theory of the transfinite needs the ordinal numbers [Hossack]
     Full Idea: The theory of the transfinite needs the ordinal numbers.
     From: Keith Hossack (Plurals and Complexes [2000], 8)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
I take the real numbers to be just lengths [Hossack]
     Full Idea: I take the real numbers to be just lengths.
     From: Keith Hossack (Plurals and Complexes [2000], 9)
     A reaction: I love it. Real numbers are beginning to get on my nerves. They turn up to the party with no invitation and improperly dressed, and then refuse to give their names when challenged.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
Transfinite ordinals are needed in proof theory, and for recursive functions and computability [Hossack]
     Full Idea: The transfinite ordinal numbers are important in the theory of proofs, and essential in the theory of recursive functions and computability. Mathematics would be incomplete without them.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], 10.1)
     A reaction: Hossack offers this as proof that the numbers are not human conceptual creations, but must exist beyond the range of our intellects. Hm.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
A plural language gives a single comprehensive induction axiom for arithmetic [Hossack]
     Full Idea: A language with plurals is better for arithmetic. Instead of a first-order fragment expressible by an induction schema, we have the complete truth with a plural induction axiom, beginning 'If there are some numbers...'.
     From: Keith Hossack (Plurals and Complexes [2000], 4)
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
In arithmetic singularists need sets as the instantiator of numeric properties [Hossack]
     Full Idea: In arithmetic singularists need sets as the instantiator of numeric properties.
     From: Keith Hossack (Plurals and Complexes [2000], 8)
Set theory is the science of infinity [Hossack]
     Full Idea: Set theory is the science of infinity.
     From: Keith Hossack (Plurals and Complexes [2000], 10)
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Numbers are properties, not sets (because numbers are magnitudes) [Hossack]
     Full Idea: I propose that numbers are properties, not sets. Magnitudes are a kind of property, and numbers are magnitudes. …Natural numbers are properties of pluralities, positive reals of continua, and ordinals of series.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], Intro)
     A reaction: Interesting! Since time can have a magnitude (three weeks) just as liquids can (three litres), it is not clear that there is a single natural property we can label 'magnitude'. Anything we can manage to measure has a magnitude.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
We can only mentally construct potential infinities, but maths needs actual infinities [Hossack]
     Full Idea: Numbers cannot be mental objects constructed by our own minds: there exists at most a potential infinity of mental constructions, whereas the axioms of mathematics require an actual infinity of numbers.
     From: Keith Hossack (Knowledge and the Philosophy of Number [2020], Intro 2)
     A reaction: Doubt this, but don't know enough to refute it. Actual infinities were a fairly late addition to maths, I think. I would think treating fictional complete infinities as real would be sufficient for the job. Like journeys which include imagined roads.
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
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.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
We are committed to a 'group' of children, if they are sitting in a circle [Hossack]
     Full Idea: By Quine's test of ontological commitment, if some children are sitting in a circle, no individual child can sit in a circle, so a singular paraphrase will have us committed to a 'group' of children.
     From: Keith Hossack (Plurals and Complexes [2000], 2)
     A reaction: Nice of why Quine is committed to the existence of sets. Hossack offers plural quantification as a way of avoiding commitment to sets. But is 'sitting in a circle' a real property (in the Shoemaker sense)? I can sit in a circle without realising it.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
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.
9. Objects / B. Unity of Objects / 3. Unity Problems / d. Coincident objects
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.
9. Objects / C. Structure of Objects / 5. Composition of an Object
Complex particulars are either masses, or composites, or sets [Hossack]
     Full Idea: Complex particulars are of at least three types: masses (which sum, of which we do not ask 'how many?' but 'how much?'); composite individuals (how many?, and summing usually fails); and sets (only divisible one way, unlike composites).
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: A composite pile of grains of sand gradually becomes a mass, and drops of water become 'water everywhere'. A set of people divides into individual humans, but redescribe the elements as the union of males and females?
The relation of composition is indispensable to the part-whole relation for individuals [Hossack]
     Full Idea: The relation of composition seems to be indispensable in a correct account of the part-whole relation for individuals.
     From: Keith Hossack (Plurals and Complexes [2000], 7)
     A reaction: This is the culmination of a critical discussion of mereology and ontological atomism. At first blush it doesn't look as if 'composition' has much chance of being a precise notion, and it will be plagued with vagueness.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
Leibniz's Law argues against atomism - water is wet, unlike water molecules [Hossack]
     Full Idea: We can employ Leibniz's Law against mereological atomism. Water is wet, but no water molecule is wet. The set of infinite numbers is infinite, but no finite number is infinite. ..But with plural reference the atomist can resist this argument.
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: The idea of plural reference is to state plural facts without referring to complex things, which is interesting. The general idea is that we have atomism, and then all the relations, unities, identities etc. are in the facts, not in the things. I like it.
The fusion of five rectangles can decompose into more than five parts that are rectangles [Hossack]
     Full Idea: The fusion of five rectangles may have a decomposition into more than five parts that are rectangles.
     From: Keith Hossack (Plurals and Complexes [2000], 8)
9. Objects / D. Essence of Objects / 3. Individual Essences
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.
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.
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.
9. Objects / D. Essence of Objects / 5. Essence as Kind
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.
9. Objects / D. Essence of Objects / 6. Essence as Unifier
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.
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?
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
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?
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?
9. Objects / D. Essence of Objects / 7. Essence and Necessity / c. Essentials are necessary
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.
9. Objects / D. Essence of Objects / 9. Essence and Properties
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.
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
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.
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).
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.
9. Objects / E. Objects over Time / 12. Origin as Essential
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?
9. Objects / F. Identity among Objects / 1. Concept of Identity
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.
10. Modality / A. Necessity / 4. De re / De dicto modality
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)
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
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).
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.
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
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.
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.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
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.
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
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.
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.
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
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)
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
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.
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.
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
Maybe personal identity is not vital in survival, and other continuations would suffice [Martin/Barresi]
     Full Idea: A modern question is whether personal identity is primarily what matters in survival; that is, people might cease and be continued by others whose continuation the original people would value as much.
     From: R Martin / J Barresi (Introduction to 'Personal Identity' [2003], p.3)
     A reaction: When put like this, the proposal seems hard to grasp. It only makes sense if you don't really believe in a thing called 'personal identity'. I don't see how you can believe in it without also believing that for you it has central importance.
Maybe we should see persons in four dimensions, with stages or time-slices at an instant [Martin/Barresi]
     Full Idea: Some recent philosophers have argued that we should replace the three-dimensional view of persons with a four-dimensional view according to which only time-slices, or 'stages', of persons exist at short intervals of time.
     From: R Martin / J Barresi (Introduction to 'Personal Identity' [2003], p.3)
     A reaction: At first glance this seems to neatly eliminate lots of traditional worries. But why would I want to retain my identity, if someone threatened to brainwash me. I also want to disown my inadequate earlier selves. Interesting, though. Lewis.
16. Persons / E. Rejecting the Self / 2. Self as Social Construct
Locke's intrinsic view of personal identity has been replaced by an externalist view [Martin/Barresi]
     Full Idea: In modern times the Lockean intrinsic relations view of personal identity has been superseded by an extrinsic relations view (also called the 'closest-continuer' or 'externalist' view).
     From: R Martin / J Barresi (Introduction to 'Personal Identity' [2003], p.1)
     A reaction: Sounds sweeping. My suspicion is that there is a raging fashion for externalist views of everything (justification, content etc.), but this will pass. I take Parfit to be the source of the modern views.
18. Thought / A. Modes of Thought / 1. Thought
A thought can refer to many things, but only predicate a universal and affirm a state of affairs [Hossack]
     Full Idea: A thought can refer to a particular or a universal or a state of affairs, but it can predicate only a universal and it can affirm only a state of affairs.
     From: Keith Hossack (Plurals and Complexes [2000], 1)
     A reaction: Hossack is summarising Armstrong's view, which he is accepting. To me, 'thought' must allow for animals, unlike language. I think Hossack's picture is much too clear-cut. Do animals grasp universals? Doubtful. Can they predicate? Yes.
27. Natural Reality / C. Space / 2. Space
We could ignore space, and just talk of the shape of matter [Hossack]
     Full Idea: We might dispense with substantival space, and say that if the distribution of matter in space could have been different, that just means the matter of the Universe could have been shaped differently (with geometry as the science of shapes).
     From: Keith Hossack (Plurals and Complexes [2000], 9)
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
For Aristotle the psyche perishes with the body (except possibly 'nous') [Martin/Barresi]
     Full Idea: In Aristotle's view, with the possible exception of 'nous' the psyche and all its parts come into being at the same time as its associated body; it is inseparable from the body, and perishes along with it.
     From: R Martin / J Barresi (Introduction to 'Personal Identity' [2003], p.8)
     A reaction: It is suggested that he thought there was only one 'nous', which all humans share (p.9). If he wants to claim that one part is immortal, he doesn't have much evidence. If psyche is the form of the body, it is bound to perish.