17 ideas
| 9967 | 'Impure' sets have a concrete member, while 'pure' (abstract) sets do not [Jubien] |
| Full Idea: Any set with a concrete member is 'impure'. 'Pure' sets are those that are not impure, and are paradigm cases of abstract entities, such as the sort of sets apparently dealt with in Zermelo-Fraenkel (ZF) set theory. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.116) | |
| A reaction: [I am unclear whether Jubien is introducing this distinction] This seems crucial in accounts of mathematics. On the one had arithmetic can be built from Millian pebbles, giving impure sets, while logicists build it from pure sets. |
| 8358 | There are no rules for the exact logic of ordinary language, because that doesn't exist [Strawson,P] |
| Full Idea: Neither Aristotelian nor Russellian rules give the exact logic of any expression of ordinary language; for ordinary language has no exact logic. | |
| From: Peter F. Strawson (On Referring [1950], §5) | |
| A reaction: This seems to imply that it is impossible to find precise logical forms, because of the pragmatic element in language, but I don't see why. Even more extreme modern pragmatics (where meaning is shifted) doesn't rule out precise underlying propositions. |
| 6413 | 'The present King of France is bald' presupposes existence, rather than stating it [Strawson,P, by Grayling] |
| Full Idea: Strawson argues that in saying 'the present King of France is bald' one is not stating that a present King of France exists, but presupposing or assuming that it does. | |
| From: report of Peter F. Strawson (On Referring [1950]) by A.C. Grayling - Russell Ch.2 | |
| A reaction: We have the notion of a leading question, such as 'when did you stop beating your wife?' But is a presupposition not simply an implied claim, as Russell said it was? |
| 8354 | Russell asks when 'The King of France is wise' would be a true assertion [Strawson,P] |
| Full Idea: The way in which Russell arrived at his analysis was by asking himself what would be the circumstances in which we would say that anyone who uttered the sentence 'The King of France is wise' had made a true assertion. | |
| From: Peter F. Strawson (On Referring [1950], §1) | |
| A reaction: This seems to connect Russell's theory of definite descriptions with the truth conditions theory of meaning which is associated (initially) with Frege. Truth will require some reference to what actually exists. |
| 9968 | A model is 'fundamental' if it contains only concrete entities [Jubien] |
| Full Idea: A first-order model can be viewed as a kind of ordered set, and if the domain of the model contains only concrete entities then it is a 'fundamental' model. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.117) | |
| A reaction: An important idea. Fundamental models are where the world of logic connects with the physical world. Any account of relationship between fundamental models and more abstract ones tells us how thought links to world. |
| 9965 | There couldn't just be one number, such as 17 [Jubien] |
| Full Idea: It makes no sense to suppose there might be just one natural number, say seventeen. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.113) | |
| A reaction: Hm. Not convinced. If numbers are essentially patterns, we might only have the number 'twelve', because we had built our religion around anything which exhibited that form (in any of its various arrangements). Nice point, though. |
| 9966 | The subject-matter of (pure) mathematics is abstract structure [Jubien] |
| Full Idea: The subject-matter of (pure) mathematics is abstract structure per se. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.115) | |
| A reaction: This is the Structuralist idea beginning to take shape after Benacerraf's launching of it. Note that Jubien gets there by his rejection of platonism, whereas some structuralist have given a platonist interpretation of structure. |
| 9964 | Since mathematical objects are essentially relational, they can't be picked out on their own [Jubien] |
| Full Idea: The essential properties of mathematical entities seem to be relational, ...so we make no progress unless we can pick out some mathematical entities wihout presupposing other entities already picked out. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.112) | |
| A reaction: [compressed] Jubien is a good critic of platonism. He has identified the problem with Frege's metaphor of a 'borehole', where we discover delightful new properties of numbers simply by reaching them. |
| 9963 | If we all intuited mathematical objects, platonism would be agreed [Jubien] |
| Full Idea: If the intuition of mathematical objects were general, there would be no real debate over platonism. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.111) | |
| A reaction: It is particularly perplexing when Gödel says that his perception of them is just like sight or smell, since I have no such perception. How do you individuate very large numbers, or irrational numbers, apart from writing down numerals? |
| 9962 | How can pure abstract entities give models to serve as interpretations? [Jubien] |
| Full Idea: I am unable to see how the mere existence of pure abstract entities enables us to concoct appropriate models to serve as interpretations. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.111) | |
| A reaction: Nice question. It is always assumed that once we have platonic realm, that everything else follows. Even if we are able to grasp the objects, despite their causal inertness, we still have to discern innumerable relations between them. |
| 9969 | The empty set is the purest abstract object [Jubien] |
| Full Idea: The empty set is the pure abstract object par excellence. | |
| From: Michael Jubien (Ontology and Mathematical Truth [1977], p.118 n8) | |
| A reaction: So a really good PhD on the empty set could crack the whole nature of reality. Get to work, whoever you are! |
| 8356 | The meaning of an expression or sentence is general directions for its use, to refer or to assert [Strawson,P] |
| Full Idea: To give the meaning of an expression is to give general directions for its use to refer to or mention particular objects or persons; in like manner, sentences are for use to make true or false assertions. | |
| From: Peter F. Strawson (On Referring [1950], §2) | |
| A reaction: The influence of Wittgenstein? I don't like it. The general idea that you can say what something is by giving directions for its use is what I think of as the Functional Fallacy: confusing the role of x with its inherent nature. Shirt as goalpost. |
| 10430 | Reference is mainly a social phenomenon [Strawson,P, by Sainsbury] |
| Full Idea: Strawson's early work gave a new direction to the study of reference by stressing that it is a social phenomenon. | |
| From: report of Peter F. Strawson (On Referring [1950]) by Mark Sainsbury - The Essence of Reference 18.2 | |
| A reaction: The question is whether speakers refer, or sentences, or expressions, or propositions. The modern consensus seems to be that some parts of language are inherently referring, but speakers combine such tools with context. Sounds right. |
| 10448 | If an expression can refer to anything, it may still instrinsically refer, but relative to a context [Bach on Strawson,P] |
| Full Idea: Strawson claimed that virtually any expression that can be used to refer to one thing in one context can be used to refer to something else in another context. Maybe expressions still refer, but only relative to a context. | |
| From: comment on Peter F. Strawson (On Referring [1950]) by Kent Bach - What Does It Take to Refer? 22.2 | |
| A reaction: If there is complete freedom, then Bach's criticism doesn't sound plausible. If something is semantically referential, that should impose pretty tight restrictions on speakers. Why distinguish names as intrinsically referential, and descriptions as not? |
| 8355 | Expressions don't refer; people use expressions to refer [Strawson,P] |
| Full Idea: 'Mentioning', or 'referring', is not something an expression does; it is something that someone can use an expression to do. | |
| From: Peter F. Strawson (On Referring [1950], §2) | |
| A reaction: That can't be whole story, because I might make a mistake when referring, so that I used the expression to refer to x, but unfortunately the words themselves referred to y. The power of language exceeds the intentions of speakers. |
| 8357 | If an utterance fails to refer then it is a pseudo-use, though a speaker may think they assert something [Strawson,P] |
| Full Idea: If an utterance is not talking about anything, then the speaker's use is not a genuine one, but a spurious or pseudo-use; he is not making either a true or a false assertion, though he may think he is. | |
| From: Peter F. Strawson (On Referring [1950], §2) | |
| A reaction: This is Strawson's verdict on 'The present King of France is bald'. His view puts speculative statements in no man's land. What do we make of 'Elvis lives' or 'phlogiston explains fire'? |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |