Combining Philosophers

All the ideas for Hermarchus, Thomas Hofweber and Joseph Melia

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65 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Metaphysics is (supposedly) first the ontology, then in general what things are like [Hofweber]
     Full Idea: Metaphysics can be divided into two parts: first ontology, which is supposed to tell us what there is in general. The second part is the rest of metaphysics, which is supposed to tell us what these things are like, in various general ways.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 01.1)
     A reaction: Hofweber is a fairly sceptical guide to metaphysics, but this has been the standard view for the last decade. Before that, Quine had set an agenda of mere ontology.
1. Philosophy / E. Nature of Metaphysics / 5. Metaphysics beyond Science
Esoteric metaphysics aims to be top science, investigating ultimate reality [Hofweber]
     Full Idea: Esoteric metaphysics appeals to those, I conjecture, who deep down hold that philosophy is the queen of sciences after all, since it investigates what the world is REALLY like.
     From: Thomas Hofweber (Ambitious, yet modest, Metaphysics [2009], 2)
     A reaction: He mentions Kit Fine and Jonathan Schaffer as esoteric metaphysicians. I see a pyramid of increasing generality and abstraction, with metaphysics at the top. This doesn't make it 'queen', though, because uncertainties multiply higher up.
1. Philosophy / E. Nature of Metaphysics / 7. Against Metaphysics
Science has discovered properties of things, so there are properties - so who needs metaphysics? [Hofweber]
     Full Idea: Material science has found that some features of metals make them more susceptible to corrosion but more resistant to fracture. Thus this immediately implies that there are features, i.e. properties. What is left for metaphysics to do?
     From: Thomas Hofweber (Ambitious, yet modest, Metaphysics [2009], 1.1)
     A reaction: Presumably economists have discovered 'features' of economies that cause unemployment, and literary critics have discovered 'features' of novels that make them good.
'Fundamentality' is either a superficial idea, or much too obscure [Hofweber]
     Full Idea: The dilemma of neo-Aristotelian metaphysics is that on an ordinary reading of prioriy, 'fundamentality' won't give the intended results, and on a metaphysical reading it turns into esoteric metaphysics.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 13.4.2)
     A reaction: Hofweber is hostile to 'esoteric' metaphysics, but sympathetic to 'egalitarian' metaphysics, which anyone can understand (with a bit of effort).
2. Reason / A. Nature of Reason / 1. On Reason
Consistency is modal, saying propositions are consistent if they could be true together [Melia]
     Full Idea: Consistency is a modal notion: a set of propositions is consistent iff all the members of the set could be true together.
     From: Joseph Melia (Modality [2003], Ch.6)
     A reaction: This shows why Kantian ethics, for example, needs a metaphysical underpinning. Maybe Kant should have believed in the reality of Leibnizian possible worlds? An account of reason requires an account of necessity and possibility.
3. Truth / H. Deflationary Truth / 1. Redundant Truth
'It's true that Fido is a dog' conjures up a contrast class, of 'it's false' or 'it's unlikely' [Hofweber]
     Full Idea: 'It's true that Fido is a dog' gives rise to a contrastive focus on 'true', with the contrast class probably depending on members like 'it's false that...' or 'it's unlikely that...'.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 02.6.3)
     A reaction: If we introduce (from linguistics) the idea of a 'contrast class', then Ramsey's famous example begins to sound meaningful. It might occur in a discussion of 'did Antony actually say 'Friends, Romans. countrymen'?'
3. Truth / H. Deflationary Truth / 3. Minimalist Truth
Instances of minimal truth miss out propositions inexpressible in current English [Hofweber]
     Full Idea: A standard objection to minimalist truth is the 'incompleteness objection'. Since there are propositions inexpressible in present English the concept of truth isn't captured by all the instances of the Tarski biconditional.
     From: Thomas Hofweber (Inexpressible Properties and Propositions [2006], 5.3)
     A reaction: Sounds like a good objection.
4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia]
     Full Idea: First-order predicate language has four connectives, two quantifiers, variables, predicates, equality, names, and brackets.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: Look up the reference for the details! The spirit of logic is seen in this basic framework, and the main interest is in the ontological commitment of the items on the list. The list is either known a priori, or it is merely conventional.
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia]
     Full Idea: First-order predicate calculus is an extensional logic, while quantified modal logic is intensional (which has grave problems of interpretation, according to Quine).
     From: Joseph Melia (Modality [2003], Ch.3)
     A reaction: The battle is over ontology. Quine wants the ontology to stick with the values of the variables (i.e. the items in the real world that are quantified over in the extension). The rival view arises from attempts to explain necessity and counterfactuals.
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Since properties can have properties, some theorists rank them in 'types' [Hofweber]
     Full Idea: Since properties themselves can have properties there is a well-known division in the theory of properties between those who take a typed and those who take a type-free approach.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 08.5)
     A reaction: I take this idea to be about linguistic predicates, and about semantics which draws on model theory. To see it as about actual 'properties' in the physical world makes no sense.
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
Maybe not even names are referential, but are just by used by speakers to refer [Hofweber]
     Full Idea: A more radical alternative which takes names not to be referring even in the broader sense, but only takes speakers to refer with uses of names.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 08.1)
     A reaction: Given that you can make up nicknames and silly nonce names for people, this seems plausible. I may say a name in a crowded room and three people look up.
5. Theory of Logic / F. Referring in Logic / 1. Naming / d. Singular terms
An adjective contributes semantically to a noun phrase [Hofweber]
     Full Idea: The semantic value of a determiner (an adjective) is a function from semantic values to nouns to semantic values of full noun phrases.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §3.1)
     A reaction: This kind of states the obvious (assuming one has a compositional view of sentences), but his point is that you can't just eliminate adjectival uses of numbers by analysing them away, as if they didn't do anything.
'Singular terms' are not found in modern linguistics, and are not the same as noun phrases [Hofweber]
     Full Idea: Being a 'singular term' is not a category in contemporary syntactic theory and it doesn't correspond to any of the notions employed there like that of a singular noun phrase or the like.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 02.3)
     A reaction: Hofweber has researched such things. This is an important objection to the reliance of modern Fregeans on the ontological commitments of singular terms (as proof that there are 'mathematical objects').
If two processes are said to be identical, that doesn't make their terms refer to entities [Hofweber]
     Full Idea: Identity between objects occurs in 'How Mary makes a chocolate cake is identical to how my grandfather used to make it', but does this show that 'how Mary makes a chocolate cake' aims to pick out an entity?
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 02.3)
     A reaction: This is a counterexample to the Fregean thought that the criterion for the existence of the referent of a singular term is its capacity to participate in an identity relation. Defenders of the Fregean view are aware of such examples.
5. Theory of Logic / G. Quantification / 1. Quantification
The quantifier in logic is not like the ordinary English one (which has empty names, non-denoting terms etc) [Hofweber]
     Full Idea: The inferential role of the existential quantifier in first order logic does not carry over to the existential quantifier in English (we have empty names, singular terms that are not even in the business of denoting, and so on).
     From: Thomas Hofweber (Ambitious, yet modest, Metaphysics [2009], 2)
The inferential quantifier focuses on truth; the domain quantifier focuses on reality [Hofweber]
     Full Idea: When we ask 'is there a number?' in its inferential role (or internalist) reading, then we ask whether or not there is a true instance of 't is a number'. When we ask in its domain conditions (externalist) reading, we ask if the world contains a number.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 03.6)
     A reaction: Hofweber's key distinction. The distinction between making truth prior and making reference prior is intriguing and important. The internalist version is close to substitutional quantification. Only the externalist view needs robust reference.
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
Quantifiers for domains and for inference come apart if there are no entities [Hofweber]
     Full Idea: Quantifiers have two functions in communication - to range over a domain of entities, and to have an inferential role (e.g. F(t)→'something is F'). In ordinary language these two come apart for singular terms not standing for any entities.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §6.3)
     A reaction: This simple observations seems to me to be wonderfully illuminating of a whole raft of problems, the sort which logicians get steamed up about, and ordinary speakers don't. Context is the key to 90% of philosophical difficulties (?). See Idea 10008.
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
Quantification can't all be substitutional; some reference is obviously to objects [Hofweber]
     Full Idea: The view that all quantification is substitutional is not very plausible in general. Some uses of quantifiers clearly seem to have the function to make a claim about a domain of objects out there, no matter how they relate to the terms in our language.
     From: Thomas Hofweber (Inexpressible Properties and Propositions [2006], 2.1)
     A reaction: Robust realists like myself are hardly going to say that quantification is just an internal language game.
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order logic needs second-order variables and quantification into predicate position [Melia]
     Full Idea: Permitting quantification into predicate position and adding second-order variables leads to second-order logic.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: Often expressed by saying that we now quantify over predicates and relations, rather than just objects. Depends on your metaphysical commitments.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
If every model that makes premises true also makes conclusion true, the argument is valid [Melia]
     Full Idea: In first-order predicate calculus validity is defined thus: an argument is valid iff every model that makes the premises of the argument true also makes the conclusion of the argument true.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: See Melia Ch. 2 for an explanation of a 'model'. Traditional views of validity tend to say that if the premises are true the conclusion has to be true (necessarily), but this introduces the modal term 'necessarily', which is controversial.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
'2 + 2 = 4' can be read as either singular or plural [Hofweber]
     Full Idea: There are two ways to read to read '2 + 2 = 4', as singular ('two and two is four'), and as plural ('two and two are four').
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §4.1)
     A reaction: Hofweber doesn't notice that this phenomenon occurs elsewhere in English. 'The team is playing well', or 'the team are splitting up'; it simply depends whether you are holding the group in though as an entity, or as individuals. Important for numbers.
Numbers are used as singular terms, as adjectives, and as symbols [Hofweber]
     Full Idea: Number words have a singular term use, and adjectival (or determiner) use, and the symbolic use. The main question is how they relate to each other.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 05.1)
     A reaction: Thus 'the number four is even', 'there are four moons', and '4 comes after 3'.
The Amazonian Piraha language is said to have no number words [Hofweber]
     Full Idea: The now famous Piraha language, of the Amazon region in Brazil, allegedly has no number words.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 05.6)
     A reaction: Two groups can be shown to be of equal cardinality, by one-to-one matching rather than by counting. They could get by using 'equals' (and maybe unequally bigger and unequally smaller), and intuitive feelings for sizes of groups.
What is the relation of number words as singular-terms, adjectives/determiners, and symbols? [Hofweber]
     Full Idea: There are three different uses of the number words: the singular-term use (as in 'the number of moons of Jupiter is four'), the adjectival (or determiner) use (as in 'Jupiter has four moons'), and the symbolic use (as in '4'). How are they related?
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §1)
     A reaction: A classic philosophy of language approach to the problem - try to give the truth-conditions for all three types. The main problem is that the first one implies that numbers are objects, whereas the others do not. Why did Frege give priority to the first?
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / f. Arithmetic
The fundamental theorem of arithmetic is that all numbers are composed uniquely of primes [Hofweber]
     Full Idea: The prime numbers are more fundamental than the even numbers, and than the composite non-prime numbers. The result that all numbers uniquely decompose into a product of prime numbers is called the 'Fundamental Theorem of Arithmetic'.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 13.4.2)
     A reaction: I could have used this example in my thesis, which defended the view that essences are the fundamentals of explanation, even in abstract theoretical realms.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
How can words be used for counting if they are objects? [Hofweber]
     Full Idea: Number words as singular terms seem to refer to objects; numbers words in determiner or adjectival position are tied to counting. How these objects are related to counting is what the application problem is about.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 06.1.3)
     A reaction: You can't use stones for counting, so there must be more to numbers than the announcement that they are 'objects'. They seem to have internal relations, which makes them unusual objects.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
Why is arithmetic hard to learn, but then becomes easy? [Hofweber]
     Full Idea: Why is arithmetic so hard to learn, and why does it seem so easy to us now? For example, subtracting 789 from 26,789.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §4.2)
     A reaction: His answer that we find thinking about objects very easy, but as children we have to learn with difficulty the conversion of the determiner/adjectival number words, so that we come to think of them as objects.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
Arithmetic is not about a domain of entities, as the quantifiers are purely inferential [Hofweber]
     Full Idea: I argue for an internalist conception of arithmetic. Arithmetic is not about a domain of entities, not even quantified entities. Quantifiers over natural numbers occur in their inferential-role reading in which they merely generalize over the instances.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §6.3)
     A reaction: Hofweber offers the hope that modern semantics can disentangle the confusions in platonist arithmetic. Very interesting. The fear is that after digging into the semantics for twenty years, you find the same old problems re-emerging at a lower level.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
Arithmetic doesn’t simply depend on objects, since it is true of fictional objects [Hofweber]
     Full Idea: That 'two dogs are more than one' is clearly true, but its truth doesn't depend on the existence of dogs, as is seen if we consider 'two unicorns are more than one', which is true even though there are no unicorns.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §6.2)
     A reaction: This is an objection to crude empirical accounts of arithmetic, but the idea would be that there is a generalisation drawn from objects (dogs will do nicely), which then apply to any entities. If unicorns are entities, it will be true of them.
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
We might eliminate adjectival numbers by analysing them into blocks of quantifiers [Hofweber]
     Full Idea: Determiner uses of number words may disappear on analysis. This is inspired by Russell's elimination of the word 'the'. The number becomes blocks of first-order quantifiers at the level of semantic representation.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §2)
     A reaction: [compressed] The proposal comes from platonists, who argue that numbers cannot be analysed away if they are objects. Hofweber says the analogy with Russell is wrong, as 'the' can't occur in different syntactic positions, the way number words can.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Logicism makes sense of our ability to know arithmetic just by thought [Hofweber]
     Full Idea: Frege's tying the objectivity of arithmetic to the objectivity of logic makes sense of the fact that can find out about arithmetic by thinking alone.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 06.1.1)
     A reaction: This assumes that logic is entirely a priori. We might compare the geometry of land surfaces with 'pure' geometry. If numbers are independent objects, it is unclear how we could have any a priori knowledge of them.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
Neo-Fregeans are dazzled by a technical result, and ignore practicalities [Hofweber]
     Full Idea: A major flaw of the neo-Fregean program is that it is more impressed by the technical result that Peano Arithmetic can be interpreted by second-order logic plus Hume's Principle, than empirical considerations about how numbers come about.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 06.1.3)
     A reaction: This doesn't sound like a problem that would bother Fregeans or neo-Fregeans much. Deriving the Peano Axioms from various beginnings has become a parlour game for modern philosophers of mathematics.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
First-order logic captures the inferential relations of numbers, but not the semantics [Hofweber]
     Full Idea: Representing arithmetic formally we do not primarily care about semantic features of number words. We are interested in capturing the inferential relations of arithmetical statements to one another, which can be done elegantly in first-order logic.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §6.3)
     A reaction: This begins to pinpoint the difference between the approach of logicists like Frege, and those who are interested in the psychology of numbers, and the empirical roots of numbers in the process of counting.
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
Supervenience offers little explanation for things which necessarily go together [Hofweber]
     Full Idea: The results from the use of supervenience in philosophical theorising are limited. In particular, modal notions can't distinguish between things which necessarily go together. For example, that truths about numbers are grounded in truths about sets.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 13.4.1)
     A reaction: [compressed]
7. Existence / D. Theories of Reality / 3. Reality
Reality can be seen as the totality of facts, or as the totality of things [Hofweber]
     Full Idea: Reality can be seen as everything that is the case - the totality of all facts that obtain - or reality can be seen as everything there is - the totality of all things that exist.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 10)
     A reaction: Things are a lot easier to specify than facts, but on the whole I prefer facts, just in order to affirm that there is more to reality than the mere 'things' that compose it. Our ontology must capture the dynamic and relational character of reality.
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
No sort of plain language or levels of logic can express modal facts properly [Melia]
     Full Idea: Some philosophers say that modal facts cannot be expressed either by name/predicate language, or by first-order predicate calculus, or even by second-order logic.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: If 'possible' were a predicate, none of this paraphernalia would be needed. If possible worlds are accepted, then the quantifiers of first-order predicate calculus will do the job. If neither of these will do, there seems to be a problem.
There are probably ineffable facts, systematically hidden from us [Hofweber]
     Full Idea: We do have reason to think that there are ineffable facts, and that these facts are systematically hidden from us.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 10.2.4)
     A reaction: [Hofweber's Ch.10 is a lengthy and interesting discussion of ineffable facts] Things which are very very small, or very very remote in space seem obvious candidates. The most obvious candidates are tiny detail about the remote past.
Maybe names and predicates can capture any fact [Melia]
     Full Idea: Some philosophers think that any fact can be captured in a language containing only names and predicates.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: The problem case Melia is discussing is modal facts, such as 'x is possible'. It is hard to see how 'possible' could be an ordinary predicate, but then McGinn claims that 'existence' is, and that there are some predicates with unusual characters.
8. Modes of Existence / B. Properties / 1. Nature of Properties
Since properties have properties, there can be a typed or a type-free theory of them [Hofweber]
     Full Idea: Since properties themselves can have properties there is a well-known division in the theory of properties between those who take a typed and those who take a type-free approach.
     From: Thomas Hofweber (Inexpressible Properties and Propositions [2006], 2.2)
     A reaction: A typed approach would imply restrictions on what it can be a property of. 'Green' is a property of surfaces, 'dark' is a property of colours. My first reaction is to opt for type-free.
9. Objects / A. Existence of Objects / 6. Nihilism about Objects
Our perceptual beliefs are about ordinary objects, not about simples arranged chair-wise [Hofweber]
     Full Idea: The belief that there are simples arranged chair-wise is not a perceptual belief. Our perceptual beliefs have a content about ordinary objects, not simples arranged chair-wise.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 07.3.1)
     A reaction: Hofweber gives ontological priority to 'perceptual beliefs'. I'm inclined to agree, but I hear the critical hordes swarming against the gate.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia]
     Full Idea: If the Identity of Indiscernibles is referring to qualitative properties, such as 'being red' or 'having mass', it is contentious; if it is referring to non-qualitative properties, such as 'member of set s' or 'brother of a', it is true but trivial.
     From: Joseph Melia (Modality [2003], Ch.3 n 11)
     A reaction: I would say 'false' rather than 'contentious'. No one has ever offered a way of distinguishing two electrons, but that doesn't mean there is just one (very busy) electron. The problem is that 'indiscernible' is only an epistemological concept.
10. Modality / A. Necessity / 2. Nature of Necessity
We may be sure that P is necessary, but is it necessarily necessary? [Melia]
     Full Idea: We may have fairly firm beliefs as to whether or not P is necessary, but many of us find ourselves at a complete loss when wondering whether or not P is necessarily necessary.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: I think it is questions like this which are pushing philosophy back towards some sort of rationalism. See Idea 3651, for example. A regress of necessities would be mad, so necessity must be taken as self-evident (in itself, though maybe not to us).
10. Modality / A. Necessity / 4. De re / De dicto modality
'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia]
     Full Idea: In cases of 'de re' modality, it is a particular thing that has the property essentially or accidentally; where the modality attaches to the proposition, it is 'de dicto' - it is the whole truth that all bachelors are unmarried that is necessary.
     From: Joseph Melia (Modality [2003], Ch.1)
     A reaction: This seems to me one of the most important distinctions in metaphysics (as practised by analytical philosophers, who like distinctions). The first type leads off into the ontology, the second type veers towards epistemology.
10. Modality / B. Possibility / 1. Possibility
Sometimes we want to specify in what ways a thing is possible [Melia]
     Full Idea: Sometimes we want to count the ways in which something is possible, or say that there are many ways in which a certain thing is possible.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: This is a basic fact about talk of 'possibility'. It is not an all-or-nothing property of a situation. There can be 'faint' possibilities of things. The proximity of some possible worlds, especially those sharing our natural laws, is one answer.
10. Modality / B. Possibility / 9. Counterfactuals
Counterfactuals are essential for planning, and learning from mistakes [Hofweber]
     Full Idea: Counterfactuals are important for reasoning about the past and to plan for the future. If we want to learn from our mistakes, it is important to think about what would have happened if I had done things differently.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 13.4.1)
     A reaction: A thought also found in Tim Williamson, but not the sort of thing you hear from Lewis or Stalnaker. It is a nice example of how highly abstract and theoretical problems need to be slotted into human psychology.
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia]
     Full Idea: In modal logic the concepts of necessity and counterfactuals are not interdefinable, so the language needs two primitives to represent them, but with the machinery of possible worlds they are defined by what is the case in all worlds, or close worlds.
     From: Joseph Melia (Modality [2003], Ch.1)
     A reaction: If your motivation is to reduce ontology to the barest of minimums (which it was for David Lewis) then it is paradoxical that the existence of possible worlds may be the way to achieve it. I doubt, though, whether a commitment to their reality is needed.
In possible worlds semantics the modal operators are treated as quantifiers [Melia]
     Full Idea: The central idea in possible worlds semantics is that the modal operators are treated as quantifiers.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: It seems an essential requirement of metaphysics that an account be given of possibility and necessity, and it is also a good dream to keep the ontology simple. Commitment to possible worlds is the bizarre outcome of this dream.
If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia]
     Full Idea: It has proved difficult to justify possible worlds semantics without accepting possible worlds. Without a secure metaphysical underpinning, the results in logic are in danger of having nothing more than a formal significance.
     From: Joseph Melia (Modality [2003], Ch.2)
     A reaction: This makes nicely clear why Lewis's controversial modal realism has to be taken seriously. It appears that the key problem is truth, because that is needed to define validity, but you can't have truth without some sort of metaphysics.
Possible worlds could be real as mathematics, propositions, properties, or like books [Melia]
     Full Idea: One can be a realist about possible worlds without adopting Lewis's extreme views; they might be abstract or mathematical entities; they might be sets of propositions or maximal uninstantiated properties; they might be like books or pictures.
     From: Joseph Melia (Modality [2003], Ch.6)
     A reaction: My intuition is that once you go down the road of realism about possible worlds, Lewis's full concrete realism looks at least as attractive as any of these options. You can discuss the 'average man' in an economic theory without realism.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
The truth of propositions at possible worlds are implied by the world, just as in books [Melia]
     Full Idea: Propositions are true at possible worlds in much the same way as they are true at books: by being implied by the book.
     From: Joseph Melia (Modality [2003], Ch.7)
     A reaction: An intriguing way to introduce the view that possible worlds should be seen as like books. The truth-makers of propositions about the actual world are items in it, but the truth-makers in novels (say) are the conditions of the whole work as united.
15. Nature of Minds / C. Capacities of Minds / 4. Objectification
Our minds are at their best when reasoning about objects [Hofweber]
     Full Idea: Our minds mainly reason about objects. Most cognitive problems we are faced with deal with particular objects, whether they are people or material things. Reasoning about them is what our minds are good at.
     From: Thomas Hofweber (Number Determiners, Numbers, Arithmetic [2005], §4.3)
     A reaction: Hofweber is suggesting this as an explanation of why we continually reify various concepts, especially numbers. Very plausible. It works for qualities of character, and explains our tendency to talk about universals as objects ('redness').
19. Language / A. Nature of Meaning / 1. Meaning
The "Fido"-Fido theory of meaning says every expression in a language has a referent [Hofweber]
     Full Idea: The picture of language often called the "Fido"-Fido theory of meaning says every expression in natural languages refers; they simply differ in what they refer to.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 08.2)
     A reaction: It seems obvious that at least there are syncategorematic terms like 'not' and 'or' and 'maybe' that are internal to language. I'm inclining to the opposite view of Paul Pietroski. Hofweber says if all words are names, they can't add up to truth.
19. Language / A. Nature of Meaning / 5. Meaning as Verification
We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia]
     Full Idea: Many philosophers now concede that it is rational to accept a proposition not because we can directly verify it but because it is supported by considerations of simplicity, theoretical utility, explanatory power and/or intuitive plausibility.
     From: Joseph Melia (Modality [2003], Ch.5)
     A reaction: This suggests how the weakness of logical positivism may have led us to the concept of epistemic virtues (such as those listed), which are, of course, largely a matter of community consensus, just as the moral virtues are.
19. Language / A. Nature of Meaning / 7. Meaning Holism / c. Meaning by Role
Inferential role semantics is an alternative to semantics that connects to the world [Hofweber]
     Full Idea: An inferential role semantics is generally seen as a large-scale alternative to a semantics based on reference and other language-world relations.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 03.4.5)
     A reaction: Presumably the other obvious language-world relation is truth. Being a robust realist, I take it I have to be strongly committed to semantics which connects to the world - or do I? Reality is robust, but our talk about it is evasive?
19. Language / C. Assigning Meanings / 1. Syntax
Syntactic form concerns the focus of the sentence, as well as the truth-conditions [Hofweber]
     Full Idea: Syntactic form is not only related to the truth conditions of a sentence; it is also related to what focus an utterance of a sentence will have.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 02.5.2)
     A reaction: Hofweber has commendably studied some linguistics. The idea of mental and linguistic 'focus' increasingly strikes me as of importance in many areas of philosophy. E.g. in the scope of ethics, on whom should you focus?
19. Language / C. Assigning Meanings / 3. Predicates
Properties can be expressed in a language despite the absence of a single word for them [Hofweber]
     Full Idea: Simply because there is no single word in a certain language for a certain property doesn't mean that it isn't expressible in that language.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 09.1.1)
     A reaction: Good. For example a shade of blue for which there is no label might be 'the next darkest discriminable shade of blue adjacent to the one we are looking at'. And then the one after that... But 'tastes better than Diet Pepsi' in ancient Greek?
'Being taller than this' is a predicate which can express many different properties [Hofweber]
     Full Idea: It is said that not every property can be expressed because there are more properties than there are predicates. ...But the same predicate can be used to express many different properties: 'being taller than this' depends on what 'this' refers to.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 09.2)
     A reaction: A good example, but being a comparative and relying on a demonstrative indexical makes it a favourable example. 'Being made of iron' doesn't have much scope for expressing many properties.
19. Language / C. Assigning Meanings / 4. Compositionality
Compositonality is a way to build up the truth-conditions of a sentence [Hofweber]
     Full Idea: Compositional semantics assigns semantic values to various expressions in order to generate the truth conditions of the sentences in which they can occur correctly, ...thus leading to the truth-conditions of the sentence.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 08.3)
     A reaction: I favour both the compositional and the truth-conditional accounts of semantics, but I am not sure how to fit the pragmatic and contextual ingredient into that picture. You can't leave out psychology.
19. Language / D. Propositions / 1. Propositions
Proposition have no content, because they are content [Hofweber]
     Full Idea: If there propositions then they do not have content, because they are content.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 08.4)
     A reaction: This sounds right. A rather obvious regress threatens if you say otherwise.
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
Without propositions there can be no beliefs or desires [Hofweber]
     Full Idea: If there are no propositions, then there are no contents, and thus there are no beliefs and desires.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 01.4.3)
     A reaction: A simple but powerful point. Those who claim that there are only sentences (and no propositions) can hardly claim that you must formulate a sentence every time you have a specific belief or desire.
19. Language / D. Propositions / 3. Concrete Propositions
Do there exist thoughts which we are incapable of thinking? [Hofweber]
     Full Idea: Might there be some thought token that has a different content than any such token we can in principle have?
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 10.3.3)
     A reaction: For me the idea that a thought might exist which can never be thought is an absurdity, but people who believe in the external existence of parts of reality called 'propositions' seem committed to it. A baffling view.
19. Language / F. Communication / 5. Pragmatics / a. Contextual meaning
'Semantic type coercion' is selecting the reading of a word to make the best sense [Hofweber]
     Full Idea: 'Semantic type coercion' is where an expression of variable type is forced to take a particular type on a particular occasion so that the sentence as a whole in which it occurse is semantically interpretable.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 05.4.4)
     A reaction: He compares 'and' in 'John sang and Mary danced' with 'John and Mary danced together', where 'and' can vary in type, and we adopt the reading that makes sense. Hofweber says we do this with number language. He favours 'cognitive need'.
19. Language / F. Communication / 5. Pragmatics / b. Implicature
'Background deletion' is appropriately omitting background from an answer [Hofweber]
     Full Idea: 'Background deletion' is the pheomenon that what isn't focused in an answer, what is the background, can be left out of the answer, with the resulting sub-sentential answer nonetheless being appropriate.
     From: Thomas Hofweber (Ontology and the Ambitions of Metaphysics [2016], 02.6.2)
     A reaction: [I'm struck by the verbosity of this sentence, from an over-long book] It is not unreasonable to think that each conversational exchange has an implicit and agreed domain of quantification. Well, 'focus', then.
19. Language / F. Communication / 6. Interpreting Language / a. Translation
Holism says language can't be translated; the expressibility hypothesis says everything can [Hofweber]
     Full Idea: Holism says that nothing that can be said in one language can be said in another one. The expressibility hypothesis says that everything that can be said in one language can be said in every other one.
     From: Thomas Hofweber (Inexpressible Properties and Propositions [2006], 6.4)
     A reaction: Obviously expressibility would only refer to reasonably comprehensive languages (with basic logical connectives, for example). Personally I vote for the expressibility hypothesis, which Hofweber seems to favour.
25. Social Practice / F. Life Issues / 6. Animal Rights
Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley]
     Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us.
     From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus
     A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts?