36 ideas
14965 | Truth rests on Elimination ('A' is true → A) and Introduction (A → 'A' is true) [Gupta] |
Full Idea: The basic principles governing truth are Truth Elimination (sentence A follows from ''A' is true') and the converse Truth Introduction (''A' is true' follows from A), which combine into Tarski's T-schema - 'A' is true if and only if A. | |
From: Anil Gupta (Truth [2001], 5.1) | |
A reaction: Introduction and Elimination rules are the basic components of natural deduction systems, so 'true' now works in the same way as 'and', 'or' etc. This is the logician's route into truth. |
14968 | A weakened classical language can contain its own truth predicate [Gupta] |
Full Idea: If a classical language is expressively weakened - for example, by dispensing with negation - then it can contain its own truth predicate. | |
From: Anil Gupta (Truth [2001], 5.2) | |
A reaction: Thus the Tarskian requirement to move to a metalanguage for truth is only a requirement of a reasonably strong language. Gupta uses this to criticise theories that dispense with the metalanguage. |
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) |
14964 | The Liar reappears, even if one insists on propositions instead of sentences [Gupta] |
Full Idea: There is the idea that the Liar paradox is solved simply by noting that truth is a property of propositions (not of sentences), and the Liar sentence does not express a proposition. But we then say 'I am not now expressing a true proposition'! | |
From: Anil Gupta (Truth [2001], 5.1) | |
A reaction: Disappointed to learn this, since I think focusing on propositions (which are unambiguous) rather than sentences solves a huge number of philosophical problems. |
14969 | Strengthened Liar: either this sentence is neither-true-nor-false, or it is not true [Gupta] |
Full Idea: An example of the Strengthened Liar is the following statement SL: 'Either SL is neither-true-nor-false or it is not true'. This raises a serious problem for any theory that assesses the paradoxes to be neither true nor false. | |
From: Anil Gupta (Truth [2001], 5.4.2) | |
A reaction: If the sentence is either true or false it reduces to the ordinary Liar. If it is neither true nor false, then it is true. |
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) |
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. |
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 |
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. |
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. |
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. |
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. |
6000 | The goal is rationality in the selection of things according to nature [Diogenes of Babylon, by Blank] |
Full Idea: Diogenes of Babylon defined the goal to be rationality in the selection and rejection of the things according to nature. | |
From: report of Diogenes (Bab) (fragments/reports [c.180 BCE]) by D.L. Blank - Diogenes of Babylon | |
A reaction: This captures the central Stoic idea quite nicely. 'Live according to nature', but this always meant 'live according to reason', because that is (as Aristotle had taught) the essence of our nature. This only makes sense if reason and nature coincide. |
5999 | The good is what is perfect by nature [Diogenes of Babylon, by Blank] |
Full Idea: Diogenes of Babylon defined the good as what is perfect by nature. | |
From: report of Diogenes (Bab) (fragments/reports [c.180 BCE]) by D.L. Blank - Diogenes of Babylon | |
A reaction: This might come close to G.E. Moore's Ideal Utilitarianism, but its dependence on the rather uneasy of concept of 'perfection' makes it questionable. Personally I find it appealing. I wish we had Diogenes' explanation. |
6001 | Justice is a disposition to distribute according to desert [Diogenes of Babylon, by Blank] |
Full Idea: Diogenes of Babylon defined justice as the disposition which distributes to everyone what he deserves. | |
From: report of Diogenes (Bab) (fragments/reports [c.180 BCE]) by D.L. Blank - Diogenes of Babylon | |
A reaction: The questions that arise would be 'what does a new-born baby deserve?', and 'what do animals deserve?', and 'does the lowest and worst of criminals deserve anything at all?' |