48 ideas
| 18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
| Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1) | |
| A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark. |
| 18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
| Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise. |
| 1618 | We study bound variables not to know reality, but to know what reality language asserts [Quine] |
| Full Idea: We look to bound variables in connection with ontology not in order to know what there is, but in order to know what a given remark or doctrine, ours or someone else's, says there is. | |
| From: Willard Quine (On What There Is [1948], p.15) |
| 8455 | Canonical notation needs quantification, variables and predicates, but not names [Quine, by Orenstein] |
| Full Idea: Quine says that names need not be part of one's canonical notation; in fact, whatever scientific purposes are accomplished by names can be carried out just as well by the devices of quantification, variables and predicates. | |
| From: report of Willard Quine (On What There Is [1948]) by Alex Orenstein - W.V. Quine Ch.2 | |
| A reaction: This is part of Quine's analysis of where the ontological commitment of a language is to be found. Kripke's notion that a name baptises an item comes as a challenge to this view. |
| 8456 | Quine extended Russell's defining away of definite descriptions, to also define away names [Quine, by Orenstein] |
| Full Idea: Quine extended Russell's theory for defining away definite descriptions, so that he could also define away names. | |
| From: report of Willard Quine (On What There Is [1948]) by Alex Orenstein - W.V. Quine Ch.2 | |
| A reaction: Quine also gets rid of universals and properties, so his ontology is squeezed from both the semantic and the metaphysical directions. Quine seems to be the key figure in modern ontology. If you want to expand it (E.J. Lowe), justify yourself to Quine. |
| 1611 | Names can be converted to descriptions, and Russell showed how to eliminate those [Quine] |
| Full Idea: I have shown that names can be converted to descriptions, and Russell has shown that descriptions can be eliminated. | |
| From: Willard Quine (On What There Is [1948], p.12) |
| 18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
| Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea. |
| 1613 | Logicists cheerfully accept reference to bound variables and all sorts of abstract entities [Quine] |
| Full Idea: The logicism of Frege, Russell, Whitehead, Church and Carnap condones the use of bound variables or reference to abstract entities known and unknown, specifiable and unspecifiable, indiscriminately. | |
| From: Willard Quine (On What There Is [1948], p.14) |
| 1616 | Formalism says maths is built of meaningless notations; these build into rules which have meaning [Quine] |
| Full Idea: The formalism of Hilbert keeps classical maths as a play of insignificant notations. Agreement is found among the rules which, unlike the notations, are quite significant and intelligible. | |
| From: Willard Quine (On What There Is [1948], p.15) |
| 1615 | Intuitionism says classes are invented, and abstract entities are constructed from specified ingredients [Quine] |
| Full Idea: The intuitionism of Poincaré, Brouwer, Weyl and others holds that classes are invented, and accepts reference to abstract entities only if they are constructed from pre-specified ingredients. | |
| From: Willard Quine (On What There Is [1948], p.14) |
| 1614 | Conceptualism holds that there are universals but they are mind-made [Quine] |
| Full Idea: Conceptualism holds that there are universals but they are mind-made. | |
| From: Willard Quine (On What There Is [1948], p.14) |
| 18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
| Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting. |
| 10241 | For Quine, there is only one way to exist [Quine, by Shapiro] |
| Full Idea: Quine takes 'existence' to be univocal, with a single ontology for his entire 'web of belief'. | |
| From: report of Willard Quine (On What There Is [1948]) by Stewart Shapiro - Philosophy of Mathematics 4.9 | |
| A reaction: Thus, there can be no 'different way of existing' (such as 'subsisting') for abstract objects such as those of mathematics. I presume that Quine's low-key physicalism is behind this. |
| 4064 | The idea of a thing and the idea of existence are two sides of the same coin [Quine, by Crane] |
| Full Idea: According to Quine's conception of existence, the idea of a thing and the idea of existence are two sides of the same coin. | |
| From: report of Willard Quine (On What There Is [1948]) by Tim Crane - Elements of Mind 1.5 | |
| A reaction: I suspect that Quine's ontology is too dependent on language, but this thought seems profoundly right |
| 19277 | Quine rests existence on bound variables, because he thinks singular terms can be analysed away [Quine, by Hale] |
| Full Idea: It is because Quine holds constant singular terms to be always eliminable by an extension of Russell's theory of definite descriptions that he takes the bound variables of first-order quantification to be the sole means by which we refer to objects. | |
| From: report of Willard Quine (On What There Is [1948]) by Bob Hale - Necessary Beings 01.2 | |
| A reaction: Hale defends a Fregean commitment to existence based on the reference of singular terms in true statements. I think they're both wrong. If you want to know what I am committed to, ask me. Don't infer it from my use of English, or logic. |
| 12210 | Quine's ontology is wrong; his question is scientific, and his answer is partly philosophical [Fine,K on Quine] |
| Full Idea: Quine's approach to ontology asks the wrong question, a scientific rather than philosophical question, and answers it in the wrong way, by appealing to philosophical considerations in addition to ordinary scientific considerations. | |
| From: comment on Willard Quine (On What There Is [1948]) by Kit Fine - The Question of Ontology p.161 | |
| A reaction: He goes on to call Quine's procedure 'cockeyed'. Presumably Quine would reply with bafflement that scientific and philosophical questions could be considered as quite different from one another. |
| 8496 | What actually exists does not, of course, depend on language [Quine] |
| Full Idea: Ontological controversy tends into controversy over language, but we must not jump to the conclusion that what there is depends on words. | |
| From: Willard Quine (On What There Is [1948], p.16) | |
| A reaction: An important corrective to my constant whinge against philosophers who treat ontology as if it were semantics, of whom Quine is the central villain. Quine was actually quite a sensible chap. |
| 1610 | To be is to be the value of a variable, which amounts to being in the range of reference of a pronoun [Quine] |
| Full Idea: To be assumed as an entity is to be reckoned as the value of a variable. This amounts roughly to saying that to be is to be in the range of reference of a pronoun. | |
| From: Willard Quine (On What There Is [1948], p.13) | |
| A reaction: Cf. Idea 7784. |
| 8459 | Fictional quantification has no ontology, so we study ontology through scientific theories [Quine, by Orenstein] |
| Full Idea: In fiction, 'Once upon a time there was an F who...' obviously does not make an ontological commitment, so Quine says the question of which ontology we accept must be dealt with in terms of the role an ontology plays in a scientific worldview. | |
| From: report of Willard Quine (On What There Is [1948]) by Alex Orenstein - W.V. Quine Ch.3 | |
| A reaction: This seems to invite questions about the ontology of people who don't espouse a scientific worldview. If your understanding of the outside world and of the past is created for you by storytellers, you won't be a Quinean. |
| 8497 | An ontology is like a scientific theory; we accept the simplest scheme that fits disorderly experiences [Quine] |
| Full Idea: Our acceptance of ontology is similar in principle to our acceptance of a scientific theory; we adopt the simplest conceptual scheme into which the disordered fragments of raw experience can be fitted and arranged. | |
| From: Willard Quine (On What There Is [1948], p.16) | |
| A reaction: Quine (who says he likes 'desert landscapes') is the modern hero for anyone who loves Ockham's Razor, and seeks extreme simplicity. And yet he finds himself committed to the existence of sets to achieve this. |
| 16261 | If commitment rests on first-order logic, we obviously lose the ontology concerning predication [Maudlin on Quine] |
| Full Idea: If Quine restricts himself to first-order predicate calculus, then the ontological implications concern the subjects of predicates. The nature of predicates, and what must be true for the predication, have disappeared from the radar screen. | |
| From: comment on Willard Quine (On What There Is [1948]) by Tim Maudlin - The Metaphysics within Physics 3.1 | |
| A reaction: Quine's response, I presume, is that the predicates can all be covered extensionally (red is a list of the red objects), and so a simpler logic will do the whole job. I agree with Maudlin though. |
| 7698 | If to be is to be the value of a variable, we must already know the values available [Jacquette on Quine] |
| Full Idea: To apply Quine's criterion that to be is to be the value of a quantifier-bound variable, we must already know the values of bound variables, which is to say that we must already be in possession of a preferred existence domain. | |
| From: comment on Willard Quine (On What There Is [1948], Ch.6) by Dale Jacquette - Ontology | |
| A reaction: [A comment on Idea 1610]. Very nice to accuse Quine, of all people, of circularity, given his attack on analytic-synthetic with the same strategy! The values will need to be known extra-lingistically, to avoid more circularity. |
| 1612 | Realism, conceptualism and nominalism in medieval universals reappear in maths as logicism, intuitionism and formalism [Quine] |
| Full Idea: The three medieval views on universals (realism, conceptualism and nominalism) reappear in the philosophy of maths as logicism, intuitionism and formalism. | |
| From: Willard Quine (On What There Is [1948], p.14) |
| 15402 | There is no entity called 'redness', and that some things are red is ultimate and irreducible [Quine] |
| Full Idea: There is not any entity whatever, individual or otherwise, which is named by the word 'redness'. ...That the houses and roses and sunsets are all of them red may be taken as ultimate and irreducible. | |
| From: Willard Quine (On What There Is [1948], p.10) | |
| A reaction: This seems to invite the 'ostrich' charge (Armstrong), that there is something left over that needs explaining. If the reds are ultimate and irreducible, that seems to imply that they have no relationship at all to one another. |
| 4443 | Quine has argued that predicates do not have any ontological commitment [Quine, by Armstrong] |
| Full Idea: Quine has attempted to bypass the problem of universals by arguing for the ontological innocence of predicates, since it is the application conditions of predicates which furnish the Realists with much of their case. | |
| From: report of Willard Quine (On What There Is [1948]) by David M. Armstrong - Universals p.503 | |
| A reaction: Presumably this would be a claim that predicates appear to commit us to properties, but that properties are not natural features, and can be reduced to something else. Tricky.. |
| 8498 | Treating scattered sensations as single objects simplifies our understanding of experience [Quine] |
| Full Idea: By bringing together scattered sense events and treating them as perceptions of one object, we reduce the complexity of our stream of experience to a manageable conceptual simplicity. | |
| From: Willard Quine (On What There Is [1948], p.17) | |
| A reaction: If, however, our consideration of tricky cases, such as vague objects, or fast-changing objects, or spatially coinciding objects made it all seem too complex, then Quine's argument would be grounds for abandoning objects. See Merricks. |
| 8856 | Quine's indispensability argument said arguments for abstracta were a posteriori [Quine, by Yablo] |
| Full Idea: Fifty years ago, Quine convinced everyone who cared that the argument for abstract objects, if there were going to be one, would have to be a posteriori in nature; an argument that numbers, for example, are indispensable entities for 'total science'. | |
| From: report of Willard Quine (On What There Is [1948], §1) by Stephen Yablo - Apriority and Existence | |
| A reaction: This sets the scene for the modern debate on the a priori. The claim that abstractions are indispensable for a factual account of the physical world strikes me as highly implausible. |
| 18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
| Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory. |
| 18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
| Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions. |
| 18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
| Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular). |
| 18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
| Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds. |
| 18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
| Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5) | |
| A reaction: They accept lots of successes in modelling necessity and time. |
| 12443 | Can an unactualized possible have self-identity, and be distinct from other possibles? [Quine] |
| Full Idea: Is the concept of identity simply inapplicable to unactualized possibles? But what sense can be found in talking of entities which cannot meaningfully be said to be identical with themselve and distinct from one another. | |
| From: Willard Quine (On What There Is [1948], p.4) | |
| A reaction: Can he seriously mean that we are not allowed to talk about possible objects? If I design a house, it is presumably identical to the house I am designing, and distinct from houses I'm not designing. |
| 18209 | We can never translate our whole language of objects into phenomenalism [Quine] |
| Full Idea: There is no likelihood that each sentence about physical objects can actually be translated, however deviously and complexly, into the phenomenalistic language. | |
| From: Willard Quine (On What There Is [1948], p.18), quoted by Penelope Maddy - Naturalism in Mathematics III.2 |
| 19682 | Internalists are much more interested in evidence than externalists are [McGrew] |
| Full Idea: The notion of evidence generally plays a much more significant role in internalist epistemologies than it does in various forms of externalism. | |
| From: Timothy McGrew (Evidence [2011], 'Prop..') | |
| A reaction: I'm guessing that this is because evidence needs a certain amount of interpretation, whereas raw facts (which externalists seem to rely on) may never even enter a mind. |
| 19684 | Does spotting a new possibility count as evidence? [McGrew] |
| Full Idea: Does the sudden realization of a heretofore unrecognized possibility count as evidence? | |
| From: Timothy McGrew (Evidence [2011], 'Evid..') | |
| A reaction: [Nice use of 'heretofore'! Why say 'previously' when you can keep these wonderful old English words alive?] This means that we can imagine new evidence ('maybe the murderer was a snake'!). Wrong. The evidence is what suggests the possibility. |
| 19687 | Absence of evidence proves nothing, and weird claims need special evidence [McGrew] |
| Full Idea: Two well know slogans (popularised by Carl Sagan) are 'absence of evidence is not evidence of absence', ...and 'extraordinary claims require extraordinary evidence'. | |
| From: Timothy McGrew (Evidence [2011], 'Absence') | |
| A reaction: [Sagan was a popular science writer and broadcaster] The second one is something like Hume's argument against miracles. The old problem of the 'missing link' for human evolution embodied the first idea. |
| 19688 | Every event is highly unlikely (in detail), but may be perfectly plausible [McGrew] |
| Full Idea: At a certain level of detail, almost any claim is unprecedented. How likely is 'Matilda won at Scrabble on Thursday with a score of 438 while drinking mint tea'? But there is nothing particularly unbelievable about the claim. | |
| From: Timothy McGrew (Evidence [2011], 'Extraordinary') | |
| A reaction: A striking idea, which rules out the simplistic idea that we can just assess evidence by its isolated likelihood. Context is crucial. How good is 438? What if she smoked opium? What if there is no Scrabble set on her island? |
| 19686 | Criminal law needs two separate witnesses, but historians will accept one witness [McGrew] |
| Full Idea: An ancient rule in law is that a criminal conviction needs evidence of two independent witnesses, but in history it is assumed that a document deserves the benefit of the doubt if it cannot be independently verified. | |
| From: Timothy McGrew (Evidence [2011], 'Interp..') | |
| A reaction: [compressed; McGrew's full account qualifies it a bit] A nice observation. One might even be suspicious of the two 'independent' witnesses, if there were lots of other reasons to doubt someon's guilt. A single weird document is also dubious. |
| 19680 | Maybe all evidence consists of beliefs, rather than of facts [McGrew] |
| Full Idea: Some philosophers have been attracted to the view that, strictly speaking, what counts as evidence is not a set of physical objects or even experiences, but rather a set of believed propositions. | |
| From: Timothy McGrew (Evidence [2011], 'Prop..') | |
| A reaction: This may be right. However, as always, I think animals are a key test. Do animals respond to evidence? Even if they did, they might need to 'make sense' of what they experienced, and even formulate a non-linguistic proposition. |
| 19681 | If all evidence is propositional, what is the evidence for the proposition? Do we face a regress? [McGrew] |
| Full Idea: Taking evidence as propositional may trade one problem for another. If the bloodstain isn't evidence, but 'this is a bloodstain' is evidence, then what serves as evidence for the belief about the bloodstain? Is there an infinite regress? | |
| From: Timothy McGrew (Evidence [2011], 'Prop..') | |
| A reaction: [compressed] I quite like evidence being propositional, but then find this. I'll retreat to my beloved coherence. I do not endorse Sellars's 'only a belief can justify a belief', because raw experience has to be part of what is coherent. |
| 19689 | Several unreliable witnesses can give good support, if they all say the same thing [McGrew] |
| Full Idea: The testimony of a number of independent witnesses, none of them particularly reliable, who give substantially the same account of some event, may provide a strong argument in its favor. | |
| From: Timothy McGrew (Evidence [2011], 'Testimonial') | |
| A reaction: A striking point. It obviously works well for panicking people in a crowd during an incident. Does it also apply to independent scientists who are known to cheat? They may not collaborate, but may all want the same result. |
| 19683 | Narrow evidentialism relies wholly on propositions; the wider form includes other items [McGrew] |
| Full Idea: Evidentialism comes in both narrow and wide forms depending on whether evidence is taken to consist only of propositions or of a wider range of items. | |
| From: Timothy McGrew (Evidence [2011], 'Evid..') | |
| A reaction: [He cites Conee and Feldman for the wide view, which is not restricted to beliefs] You can hardly rely on occurrent beliefs as evidence, so we often have good knowledge with forgotten justification. But such knowledge has been 'weakened'. |
| 19685 | Falsificationism would be naive if even a slight discrepancy in evidence killed a theory [McGrew] |
| Full Idea: Data do not quite speak for themselves, which speaks against a naive form of falsificationism according to which even the slightest mismatch between theory and evidence suffices to overturn a theory. | |
| From: Timothy McGrew (Evidence [2011], 'Interp..') | |
| A reaction: [He cites Robert Boyle wisely ignoring some data to get a good fit for his graph] |
| 1619 | There is an attempt to give a verificationist account of meaning, without the error of reducing everything to sensations [Dennett on Quine] |
| Full Idea: This essay offered a verificationist account of language without the logical positivist error of supposing that verification could be reduced to a mere sequence of sense-experiences. | |
| From: comment on Willard Quine (On What There Is [1948]) by Daniel C. Dennett - works | |
| A reaction: This is because of Quine's holistic view of theory, so that sentences are not tested individually, where sense-data might be needed as support, but as whole teams which need to be simple, coherent etc. |
| 1617 | The word 'meaning' is only useful when talking about significance or about synonymy [Quine] |
| Full Idea: The useful ways in which ordinary people talk about meanings boil down to two: the having of meanings, which is significance, and sameness of meaning, or synonymy. | |
| From: Willard Quine (On What There Is [1948], p.11) | |
| A reaction: If the Fregean criterion for precise existence is participation in an identity relation, then synonymy does indeed pinpoint what we mean by 'meaning. |
| 1609 | I do not believe there is some abstract entity called a 'meaning' which we can 'have' [Quine] |
| Full Idea: Some philosophers construe meaningfulness as the having (in some sense of 'having') of some abstract entity which he calls a meaning, whereas I do not. | |
| From: Willard Quine (On What There Is [1948], p.11) | |
| A reaction: To call a meaning an 'entity' is to put a spin on it that makes it very implausible. Introspection shows us a gap between grasping a word and grasping its meaning. |
| 19159 | Quine relates predicates to their objects, by being 'true of' them [Quine, by Davidson] |
| Full Idea: Quine relates predicates to the things of which they can be predicated ...and hence predicates are 'true of' each and every thing of which the predicate can be truly predicated. | |
| From: report of Willard Quine (On What There Is [1948]) by Donald Davidson - Truth and Predication 5 | |
| A reaction: Davidson comments that the virtue of Quine's view is negative, in avoiding a regress in the explanation of predication. I'm not sure about true 'of' as an extra sort of truth, but I like dropping predicates from ontology, and sticking to truths. |