20 ideas
| 22438 | Philosophy is largely concerned with finding the minimum that science could get by with [Quine] |
| Full Idea: Philosophy is in large part concerned with ...what science could get along with, could be reconstructed by means of, as distinct from what science has historically made us of. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: This nicely summarises the programme for the whole of the philosophy of David Lewis, who was Quine's pupil. If you start by asking what it could 'get by with', it is not surprising that simplicity is the top intellectual virtue for both of them. |
| 22436 | Logicians don't paraphrase logic into language, because they think in the symbolic language [Quine] |
| Full Idea: The logician does not even need to paraphrase the vernacular into his logical notation, for he has learned to think directly in his logical notation, or even (which is the beauty of the thing) to let it think for him. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: See Williamson's love of logic (and his book on modal metaphysics). This idea embodies the dream of hardcore Frege-Russellian analytic philosophers. I wish someone had told me when I studied logic that the target was to actually think symbolically. |
| 22431 | Good algorithms and theories need many occurrences of just a few elements [Quine] |
| Full Idea: The power and simplicity of an algorithm, or indeed of any theory, depend on there being many occurrences of few elements rather than few occurrences of many. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], III) | |
| A reaction: Not sure how this applies to a software function. One which produces a good result from a large number of input variables sounds particularly impressive to me. Many occurrences of a single variable sounds rather inefficient. |
| 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) |
| 22435 | The logician's '→' does not mean the English if-then [Quine] |
| Full Idea: The logician drops 'if-then' in favour of '→' without ever entertaining the mistaken idea that they are synonymous. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: [Quine uses the older horseshoe symbol] The conditional in English is not well understood, whereas the symbol is unambiguous. A warning to myself, since I have a tendency to translate symbols into English all the time. [p.156 'implies' is worse!] |
| 22433 | It is important that the quantification over temporal entities is timeless [Quine] |
| Full Idea: It would be hard to exaggerate the importance of recognising the timelessness of quantification over temporal entities. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], IV) | |
| A reaction: 'Some moments in this cricket match were crucial'. The domain is not timeless, but consists of moments in this match. Can you say the quantifier is timeless but its domain is not? Only in the sense that 'very' is a timeless word, I think. |
| 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) |
| 22437 | Logical languages are rooted in ordinary language, and that connection must be kept [Quine] |
| Full Idea: A logical language is not independent of ordinary language. It has its roots in ordinary language, and these roots are not to be severed. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: Music to my ears. When you study logic, no one has to teach you what the words 'or' and 'if-then' mean, but they are disambiguated by the symbolism. The roots of logic are in ordinary talk of 'and', 'or' and 'not', which is the real world. |
| 22434 | Reduction to logical forms first simplifies idioms and grammar, then finds a single reading of it [Quine] |
| Full Idea: Ordinary language is reduced to logical form in two ways: reduction of the variety of idioms and grammatical constructions, and reduction of each surviving idiom to one fixed and convenient interpretation. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: Is there a conflict between a 'fixed' and a 'convenient' result? By 'fixed' I suppose he means it is a commitment (to not waver). What is the logical form of a sentence which is deliberately ambiguous? |
| 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) |
| 22432 | Normally conditionals have no truth value; it is the consequent which has a conditional truth value [Quine] |
| Full Idea: Ordinarily the conditional is not thought of as true or false at all, but rather the consequent is thought of as conditionally true or false given the antecedent. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], III) | |
| A reaction: At first this seems obvious, but a conditional asserts a relationship between two propositions, and so presumably it is true if that relationship exists. 'Is it actually true that if it is Monday then everyone in the office is depressed?'. |
| 19729 | 'Modal epistemology' demands a connection between the belief and facts in possible worlds [Black,T] |
| Full Idea: In 'modal epistemologies' a belief counts as knowledge only if there is a modal connection - a connection not only to the actual world, but also to other non-actual possible worlds - between the belief and the facts of the matter. | |
| From: Tim Black (Modal and Anti-Luck Epistemology [2011], 1) | |
| A reaction: [Pritchard 2005 seems to be a source for this] This sounds to me a bit like Nozick's tracking or sensitivity theory. Nozick is, I suppose, diachronic (time must pass, for the tracking), where this theory is synchronic. |
| 19728 | Gettier and lottery cases seem to involve luck, meaning bad connection of beliefs to facts [Black,T] |
| Full Idea: The protagonists in Gettier cases and in lottery cases fail to have knowledge because their beliefs are true simply as a matter of luck, where this means that their beliefs themselves are not appropriately connected to the facts. | |
| From: Tim Black (Modal and Anti-Luck Epistemology [2011], 1) | |
| A reaction: The lottery problem is you correctly believe 'my ticket won't win the lottery' even though you don't seem to actually know it won't. Is the Gettier problem simply the problem of lucky knowledge? 'Luck' is a rather vague concept. |
| 22430 | If we understand a statement, we know the circumstances of its truth [Quine] |
| Full Idea: We understand under what circumstances to say of any given statement that it is true, just as clearly as we understand the statement itself. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], II) | |
| A reaction: This probably shouldn't be taken as a theory of meaning (in which Quine doesn't really believe) but as a plausible statement of correlated facts. Hypothetical assertions might be a problem case. 'If only I could be in two places at once'? |
| 13713 | Quine holds time to be 'space-like': past objects are as real as spatially remote ones [Quine, by Sider] |
| Full Idea: Quine's view is that time is 'space-like'. Past objects are as real as present ones; they're just temporally distant, just as spatially distant objects are just as real as the ones around here. | |
| From: report of Willard Quine (Mr Strawson on Logical Theory [1953]) by Theodore Sider - Logic for Philosophy 7.3.1 | |
| A reaction: Something is a wrong with a view that says that a long-dead person is just as real as one currently living. Death is rather more than travelling to a distant place. Arthur Prior responded to Quine by saying 'tense operators' are inescapable. |