47 ideas
21634 | 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. |
21666 | '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). |
21640 | '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'?' |
21657 | 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. |
8729 | Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro] |
Full Idea: Intuitionists in mathematics deny excluded middle, because it is symptomatic of faith in the transcendent existence of mathematical objects and/or the truth of mathematical statements. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2) | |
A reaction: There are other problems with excluded middle, such as vagueness, but on the whole I, as a card-carrying 'realist', am committed to the law of excluded middle. |
21653 | 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. |
21636 | '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'). |
21637 | 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. |
21643 | 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. |
21644 | 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'. |
21646 | 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. |
8763 | The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro] |
Full Idea: It is surely wise to identify the positions in the natural numbers structure with their counterparts in the integer, rational, real and complex number structures. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2) | |
A reaction: The point is that this might be denied, since 3, 3/1, 3.00.., and -3*i^2 are all arrived at by different methods of construction. Natural 3 has a predecessor, but real 3 doesn't. I agree, intuitively, with Shapiro. Russell (1919) disagreed. |
18249 | Cauchy gave a formal definition of a converging sequence. [Shapiro] |
Full Idea: A sequence a1,a2,... of rational numbers is 'Cauchy' if for each rational number ε>0 there is a natural number N such that for all natural numbers m, n, if m>N and n>N then -ε < am - an < ε. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 7.2 n4) | |
A reaction: The sequence is 'Cauchy' if N exists. |
21665 | 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. |
21649 | 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. |
8764 | Categories are the best foundation for mathematics [Shapiro] |
Full Idea: There is a dedicated contingent who hold that the category of 'categories' is the proper foundation for mathematics. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 10.3 n7) | |
A reaction: He cites Lawvere (1966) and McLarty (1993), the latter presenting the view as a form of structuralism. I would say that the concept of a category will need further explication, and probably reduce to either sets or relations or properties. |
8762 | Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro] |
Full Idea: Zermelo said that for each number n, its successor is the singleton of n, so 3 is {{{null}}}, and 1 is not a member of 3. Von Neumann said each number n is the set of numbers less than n, so 3 is {null,{null},{null,{null}}}, and 1 is a member of 3. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2) | |
A reaction: See Idea 645 - Zermelo could save Plato from the criticisms of Aristotle! These two accounts are cited by opponents of the set-theoretical account of numbers, because it seems impossible to arbitrate between them. |
8760 | Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro] |
Full Idea: The structuralist vigorously rejects any sort of ontological independence among the natural numbers; the essence of a natural number is its relations to other natural numbers. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1) | |
A reaction: This seems to place the emphasis on ordinals (what order?) rather than on cardinality (how many?). I am strongly inclined to think that this is the correct view, though you can't really have relations if there is nothing to relate. |
8761 | A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro] |
Full Idea: A 'system' is a collection of objects with certain relations among them; a 'pattern' or 'structure' is the abstract form of a system, highlighting the interrelationships and ignoring any features they do not affect how they relate to other objects. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1) | |
A reaction: Note that 'ignoring' features is a psychological account of abstraction, which (thanks to Frege and Geach) is supposed to be taboo - but which I suspect is actually indispensable in any proper account of thought and concepts. |
21647 | 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. |
21648 | 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. |
8744 | Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro] |
Full Idea: The thesis that principles of arithmetic are derivable from the laws of logic runs against a now common view that logic itself has no ontology. There are no particular logical objects. From this perspective logicism is a non-starter. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 5.1) | |
A reaction: This criticism strikes me as utterly devastating. There are two routes to go: prove that logic does have an ontology of objects (what would they be?), or - better - deny that arithmetic contains any 'objects'. Or give up logicism. |
8749 | Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro] |
Full Idea: Term Formalism is the view that mathematics is just about characters or symbols - the systems of numerals and other linguistic forms. ...This will cover integers and rational numbers, but what are real numbers supposed to be, if they lack names? | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.1) | |
A reaction: Real numbers (such as pi and root-2) have infinite decimal expansions, so we can start naming those. We could also start giving names like 'Harry' to other reals, though it might take a while. OK, I give up. |
8750 | Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro] |
Full Idea: Game Formalism likens mathematics to chess, where the 'content' of mathematics is exhausted by the rules of operating with its language. ...This, however, leaves the problem of why the mathematical games are so useful to the sciences. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.2) | |
A reaction: This thought pushes us towards structuralism. It could still be a game, but one we learned from observing nature, which plays its own games. Chess is, after all, modelled on warfare. |
8752 | Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro] |
Full Idea: The Deductivist version of formalism (sometimes called 'if-thenism') says that the practice of mathematics consists of determining logical consequences of otherwise uninterpreted axioms. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 6.2) | |
A reaction: [Hilbert is the source] More plausible than Term or Game Formalism (qv). It still leaves the question of why it seems applicable to nature, and why those particular axioms might be chosen. In some sense, though, it is obviously right. |
8753 | Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro] |
Full Idea: Critics commonly complain that the intuitionist restrictions cripple the mathematician. On the other hand, intuitionist mathematics allows for many potentially important distinctions not available in classical mathematics, and is often more subtle. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 7.1) | |
A reaction: The main way in which it cripples is its restriction on talk of infinity ('Cantor's heaven'), which was resented by Hilbert. Since high-level infinities are interesting, it would be odd if we were not allowed to discuss them. |
8731 | Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro] |
Full Idea: I classify conceptualists according to what they say about properties or concepts. If someone classified properties as existing independent of language I would classify her as a realist in ontology of mathematics. Or they may be idealists or nominalists. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 2.2.1) | |
A reaction: In other words, Shapiro wants to eliminate 'conceptualist' as a useful label in philosophy of mathematics. He's probably right. All thought involves concepts, but that doesn't produce a conceptualist theory of, say, football. |
8730 | 'Impredicative' definitions refer to the thing being described [Shapiro] |
Full Idea: A definition of a mathematical entity is 'impredicative' if it refers to a collection that contains the defined entity. The definition of 'least upper bound' is impredicative as it refers to upper bounds and characterizes a member of this set. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2) | |
A reaction: The big question is whether mathematics can live with impredicative definitions, or whether they threaten to be viciously circular, and undermine the whole enterprise. |
21664 | 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] |
21660 | 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. |
21661 | 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. |
21652 | 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. |
21663 | 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. |
8725 | Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro] |
Full Idea: Rationalism is a long-standing school that can be characterized as an attempt to extend the perceived methodology of mathematics to all of knowledge. | |
From: Stewart Shapiro (Thinking About Mathematics [2000], 1.1) | |
A reaction: Sometimes called 'Descartes's Dream', or the 'Enlightenment Project', the dream of proving everything. Within maths, Hilbert's Programme aimed for the same certainty. Idea 22 is the motto for the opposition to this approach. |
21654 | 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. |
21641 | 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? |
21638 | 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? |
21658 | 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? |
21659 | '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. |
21655 | 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. |
21656 | 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. |
21635 | 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. |
21662 | 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. |
21645 | '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'. |
21639 | '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. |
22381 | Being a good father seems to depend on intentions, rather than actual abilities [Foot] |
Full Idea: Being a good father, or daughter, or friend seems to depend on one's intentions, rather than on such things as cleverness and strength. | |
From: Philippa Foot (Goodness and Choice [1961], p.138) | |
A reaction: Not sure about that. In wartime a good father might need to be actually brave, and in times of hardship be actually economically successful. 'He meant well, but he was a hopeless father'? |
22380 | Some words, such as 'knife', have a meaning which involves its function [Foot] |
Full Idea: The word 'knife' names an object in respect of its function. That is not to say (simply) that it names an object which has a function, but also that the function is involved in the meaning of the word. | |
From: Philippa Foot (Goodness and Choice [1961], p.134) | |
A reaction: It seems faintly possible that someone (a child, perhaps) could know the word and recognise the object, but not know what the object is for. Ditto with other things which have functional names. |