13 ideas
| 22153 | Quine rejects Carnap's view that science and philosophy are distinct [Quine, by Boulter] |
| Full Idea: Quine rejects Carnap's view that the methods of science and philosophy are distinct. | |
| From: report of Willard Quine (On Carnap's Views on Ontology [1951]) by Stephen Boulter - Why Medieval Philosophy Matters 5 | |
| A reaction: I can't decide this one. Leibniz agreed with Carnap, but rated philosophy more highly. I like the view of philosophy as continuous with science, but that doesn't make it a branch of science. I incline towards science being a branch of philosophy. |
| 10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
| Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion. | |
| From: JC Beall / G Restall (Logical Consequence [2005], Intro) |
| 10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
| Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
| A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski. |
| 10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
| Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
| Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists). | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
| A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one. |
| 10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
| Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 2) |
| 10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
| Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 4) | |
| A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules. |
| 10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
| Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language. | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
| Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives). | |
| From: JC Beall / G Restall (Logical Consequence [2005], 3) |
| 19485 | Names have no ontological commitment, because we can deny that they name anything [Quine] |
| Full Idea: I think there is no commitment to entities through use of alleged names of them; other things being equal, we can always deny the allegation that the words in question are names. | |
| From: Willard Quine (On Carnap's Views on Ontology [1951], p.205) | |
| A reaction: Hm. So why can't you deny that variables actually refer to existing entities? If I say 'I just saw James', it's a bit cheeky to then deny that James refers to anyone. He uses Russell's technique to paraphrase names. |
| 19486 | We can use quantification for commitment to unnameable things like the real numbers [Quine] |
| Full Idea: Through our variables of quantification we are quite capable of committing ourselves to entities which cannot be named individually at all in the resources of our language; witness the real numbers. | |
| From: Willard Quine (On Carnap's Views on Ontology [1951], p.205) | |
| A reaction: The real numbers are uncountable, and thus cannot all be named. This is quite an impressive point. I've always had doubts about the existence of real numbers, on the grounds that they could never all be named. |
| 17535 | Dispositionality has its own distinctive type of modality [Mumford/Anjum] |
| Full Idea: We contend that dispositionality involves a non-alethic, sui generis, irreducible modality. | |
| From: S.Mumford/R.Lill Anjum (Dispositional Modality [2011], 1) | |
| A reaction: This is a lovely bold proposal, and seems to be supported by Werner Heisenberg, in Idea 17534. |
| 19487 | Without the analytic/synthetic distinction, Carnap's ontology/empirical distinction collapses [Quine] |
| Full Idea: If there is no proper distinction between analytic and synthetic, then no basis at all remains for the contrast which Carnap urges between ontological statements and empirical statements of existence. Ontology then ends up on a par with natural science. | |
| From: Willard Quine (On Carnap's Views on Ontology [1951], p.211) | |
| A reaction: Carnap says ontology is relative to a linguistic framework. 'External' ontology is empty. This quotation gives Quine's main motivation for denying the analytic/synthetic distinction. |