19 ideas
| 11064 | Classes can be reduced to propositional functions [Russell, by Hanna] |
| Full Idea: Russell held that classes can be reduced to propositional functions. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908]) by Robert Hanna - Rationality and Logic 2.4 | |
| A reaction: The exact nature of a propositional function is disputed amongst Russell scholars (though it is roughly an open sentence of the form 'x is red'). |
| 9038 | We must distinguish what the speaker denotes by a name, from what the name denotes [Evans] |
| Full Idea: There are two related but distinguishable questions concerning proper names: what the speaker denotes (upon an occasion), and what the name denotes. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §I) | |
| A reaction: I don't think any account of language makes sense without this sort of distinction, as in my favourite example: the password is 'swordfish'. So how does language gets its own meanings, independent of what speakers intend? |
| 5824 | How can an expression be a name, if names can change their denotation? [Evans] |
| Full Idea: We need an account of what makes an expression into a name for something that will allow names to change their denotations. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §II) | |
| A reaction: Presumably an example would be 'The Prime Minister is in the building'. Evans proposes to discuss communication, rather than strict meanings and descriptions. |
| 9042 | A private intention won't give a name a denotation; the practice needs it to be made public [Evans] |
| Full Idea: Intentions alone don't bring it about that a name gets a denotation; without the intention being manifest there cannot be the common knowledge required for the practice. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §II) | |
| A reaction: Well, I might have a private name for some hated colleague which I mutter to myself whenever I see her. The way names, and language generally, becomes ossified is by joining the great impersonal sea of the language. ..waves of bones, |
| 9041 | The Causal Theory of Names is wrong, since the name 'Madagascar' actually changed denotation [Evans] |
| Full Idea: Change of denotation is decisive against the Causal Theory of Names. Changes of denotation actually occur: a hearsay report misunderstood by Marco Polo transferred the name 'Madagascar' from a portion of the mainland to the African island. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §I) | |
| A reaction: This doesn't sound decisive, as you could give an intermediate causal account of Marco Polo's mistake. I might take the famous name Winston, and baptise my son with it. And I might have done it because I thought Winston was a German dictator. |
| 6407 | The class of classes which lack self-membership leads to a contradiction [Russell, by Grayling] |
| Full Idea: The class of teaspoons isn't a teaspoon, so isn't a member of itself; but the class of non-teaspoons is a member of itself. The class of all classes which are not members of themselves is a member of itself if it isn't a member of itself! Paradox. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908]) by A.C. Grayling - Russell Ch.2 | |
| A reaction: A very compressed version of Russell's famous paradox, often known as the 'barber' paradox. Russell developed his Theory of Types in an attempt to counter the paradox. Frege's response was to despair of his own theory. |
| 10418 | Type theory seems an extreme reaction, since self-exemplification is often innocuous [Swoyer on Russell] |
| Full Idea: Russell's reaction to his paradox (by creating his theory of types) seems extreme, because many cases of self-exemplification are innocuous. The property of being a property is itself a property. | |
| From: comment on Bertrand Russell (Mathematical logic and theory of types [1908]) by Chris Swoyer - Properties 7.5 | |
| A reaction: Perhaps it is not enough that 'many cases' are innocuous. We are starting from philosophy of mathematics, where precision is essentially. General views about properties come later. |
| 10047 | Russell's improvements blocked mathematics as well as paradoxes, and needed further axioms [Russell, by Musgrave] |
| Full Idea: Unfortunately, Russell's new logic, as well as preventing the deduction of paradoxes, also prevented the deduction of mathematics, so he supplemented it with additional axioms, of Infinity, of Choice, and of Reducibility. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908]) by Alan Musgrave - Logicism Revisited §2 | |
| A reaction: The first axiom seems to be an empirical hypothesis, and the second has turned out to be independent of logic and set theory. |
| 23478 | Type theory means that features shared by different levels cannot be expressed [Morris,M on Russell] |
| Full Idea: Russell's theory of types avoided the paradoxes, but it had the result that features common to different levels of the hierarchy become uncapturable (since any attempt to capture them would involve a predicate which disobeyed the hierarchy restrictions). | |
| From: comment on Bertrand Russell (Mathematical logic and theory of types [1908]) by Michael Morris - Guidebook to Wittgenstein's Tractatus 2H |
| 21718 | Ramified types can be defended as a system of intensional logic, with a 'no class' view of sets [Russell, by Linsky,B] |
| Full Idea: A defence of the ramified theory of types comes in seeing it as a system of intensional logic which includes the 'no class' account of sets, and indeed the whole development of mathematics, as just a part. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908]) by Bernard Linsky - Russell's Metaphysical Logic 6.1 | |
| A reaction: So Linsky's basic project is to save logicism, by resting on intensional logic (rather than extensional logic and set theory). I'm not aware that Linsky has acquired followers for this. Maybe Crispin Wright has commented? |
| 18126 | A set does not exist unless at least one of its specifications is predicative [Russell, by Bostock] |
| Full Idea: The idea is that the same set may well have different canonical specifications, i.e. there may be different ways of stating its membership conditions, and so long as one of these is predicative all is well. If none are, the supposed set does not exist. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908]) by David Bostock - Philosophy of Mathematics 8.1 |
| 18128 | Russell is a conceptualist here, saying some abstracta only exist because definitions create them [Russell, by Bostock] |
| Full Idea: It is a conceptualist approach that Russell is relying on. ...The view is that some abstract objects ...exist only because they are definable. It is the definition that would (if permitted) somehow bring them into existence. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908]) by David Bostock - Philosophy of Mathematics 8.1 | |
| A reaction: I'm suddenly thinking that predicativism is rather interesting. Being of an anti-platonist persuasion about abstract 'objects', I take some story about how we generate them to be needed. Psychological abstraction seems right, but a bit vague. |
| 18124 | Vicious Circle says if it is expressed using the whole collection, it can't be in the collection [Russell, by Bostock] |
| Full Idea: The Vicious Circle Principle says, roughly, that whatever involves, or presupposes, or is only definable in terms of, all of a collection cannot itself be one of the collection. | |
| From: report of Bertrand Russell (Mathematical logic and theory of types [1908], p.63,75) by David Bostock - Philosophy of Mathematics 8.1 | |
| A reaction: This is Bostock's paraphrase of Russell, because Russell never quite puts it clearly. The response is the requirement to be 'predicative'. Bostock emphasises that it mainly concerns definitions. The Principle 'always leads to hierarchies'. |
| 5825 | Speakers intend to refer to items that are the source of their information [Evans] |
| Full Idea: In general, a speaker intends to refer to the item that is the dominant source of his associated body of information. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §II) | |
| A reaction: This sounds like a theory of reference which fully preserves the spirit of traditional empiricism. Speakers refer to ideas which connect to the source of their underlying impressions. |
| 5823 | The intended referent of a name needs to be the cause of the speaker's information about it [Evans] |
| Full Idea: A necessary (but not sufficient) condition for x's being the intended referent of S's use of a name is that x should be the source of the causal origin of the body of information that S has associated with the name. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §I) | |
| A reaction: This is Evans's adaptation of Kripke's causal theory of names. This cries out for a counterexample. I say something about General Montgomery, having just listened to 'Monty's Double' give a talk, believing it was Montgomery? |
| 9039 | If descriptions are sufficient for reference, then I must accept a false reference if the descriptions fit [Evans] |
| Full Idea: The strong thesis (that descriptions are sufficient for reference) is outrageous. It would mean that if Mr X is wrongly introduced to me as Mr Y, then I truly say 'this is Mr Y' if X overwhelmingly satisfies descriptions of Y. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §I) | |
| A reaction: [I omit some qualifying phrases] Evans says that probably no one ever held this view. It seems right. In the case of an electron it would seem that all the descriptions could be the same, except space-time location. Same electron as yesterday? |
| 9043 | We use expressions 'deferentially', to conform to the use of other people [Evans] |
| Full Idea: Sometimes we use expressions with the overriding intention to conform to the use made of them by some other person or persons. I shall say we use the expression 'deferentially'; examples might be 'viol' or 'minuet'. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §II) | |
| A reaction: I presume Evans wasn't very musical. This label sounds useful, if you wish to connect Grice's account of meaning with Putnam's externalist account of concepts, where deference to experts is crucial. Is all linguistic usage deferential? |
| 9040 | Charity should minimize inexplicable error, rather than maximising true beliefs [Evans] |
| Full Idea: I think the Principle of Charity (maximise true beliefs) is unacceptable. The acceptable principle enjoins minimizing the attribution of inexplicable error and cannot be operated without a theory of the causation of belief for the creatures investigated. | |
| From: Gareth Evans (The Causal Theory of Names [1973], §I) | |
| A reaction: The normal principle of charity certainly seems on shaky ground if you think you have encountered a fairly normal tribe, when they in fact are in possession of the weirdest belief system on the entire planet. |
| 20422 | The experience of expression and communication are intermingled in art [Croce] |
| Full Idea: It is very difficult to perceive the frontier between expression and communication in actual fact, for the two processes usually alternate rapidly and are almost intermingled. | |
| From: Benedetto Croce (The Essence of Aesthetic [1912]), quoted by Gary Kemp - Croce and Collingwood | |
| A reaction: [text unsure] I think he is getting at seeing the painting (or whatever) as a physical object, and seeing it as the experience which results from the object. The alternation of the objective and subjective views. Reminds me of Thomas Nagel. |