22 ideas
| 17641 | Discoveries in mathematics can challenge philosophy, and offer it a new foundation [Russell] |
| Full Idea: Any new discovery as to mathematical method and principles is likely to upset a great deal of otherwise plausible philosophising, as well as to suggest a new philosophy which will be solid in proportion as its foundations in mathematics are securely laid. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.283) | |
| A reaction: This is a manifesto for modern analytic philosophy. I'm not convinced, especially if a fictionalist view of maths is plausible. What Russell wants is rigour, but there are other ways of getting that. Currently I favour artificial intelligence. |
| 17638 | If one proposition is deduced from another, they are more certain together than alone [Russell] |
| Full Idea: Two obvious propositions of which one can be deduced from the other both become more certain than either in isolation; thus in a complicated deductive system, many parts of which are obvious, the total probability may become all but absolute certainty. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.279) | |
| A reaction: Thagard picked this remark out, in support of his work on coherence. |
| 17632 | Non-contradiction was learned from instances, and then found to be indubitable [Russell] |
| Full Idea: The law of contradiction must have been originally discovered by generalising from instances, though, once discovered, it was found to be quite as indubitable as the instances. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.274) |
| 17962 | The truth-maker principle is that every truth has a sufficient truth-maker [Forrest] |
| Full Idea: Item x is said to be a sufficient truth-maker for truth-bearer p just in case necessarily if x exists then p is true. ...Every truth has a sufficient truth-maker. Hence, I take it, the sum of all sufficient truth-makers is a universal truth-maker. | |
| From: Peter Forrest (General Facts,Phys Necessity, and Metaph of Time [2006], 1) | |
| A reaction: Note that it is not 'necessary', because something else might make p true instead. |
| 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. |
| 17629 | Which premises are ultimate varies with context [Russell] |
| Full Idea: Premises which are ultimate in one investigation may cease to be so in another. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.273) |
| 17630 | The sources of a proof are the reasons why we believe its conclusion [Russell] |
| Full Idea: In mathematics, except in the earliest parts, the propositions from which a given proposition is deduced generally give the reason why we believe the given proposition. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.273) |
| 17640 | Finding the axioms may be the only route to some new results [Russell] |
| Full Idea: The premises [of a science] ...are pretty certain to lead to a number of new results which could not otherwise have been known. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.282) | |
| A reaction: I identify this as the 'fruitfulness' that results when the essence of something is discovered. |
| 17627 | It seems absurd to prove 2+2=4, where the conclusion is more certain than premises [Russell] |
| Full Idea: It is an apparent absurdity in proceeding ...through many rather recondite propositions of symbolic logic, to the 'proof' of such truisms as 2+2=4: for it is plain that the conclusion is more certain than the premises, and the supposed proof seems futile. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.272) | |
| A reaction: Famously, 'Principia Mathematica' proved this fact at enormous length. I wonder if this thought led Moore to his common sense view of his own hand - the conclusion being better than the sceptical arguments? |
| 17628 | Arithmetic was probably inferred from relationships between physical objects [Russell] |
| Full Idea: When 2 + 2 =4 was first discovered, it was probably inferred from the case of sheep and other concrete cases. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.272) |
| 17637 | The most obvious beliefs are not infallible, as other obvious beliefs may conflict [Russell] |
| Full Idea: Even where there is the highest degree of obviousness, we cannot assume that we are infallible - a sufficient conflict with other obvious propositions may lead us to abandon our belief, as in the case of a hallucination afterwards recognised as such. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.279) | |
| A reaction: This approach to fallibilism seems to arise from the paradox that undermined Frege's rather obvious looking axioms. After Peirce and Russell, fallibilism has become a secure norm of modern thought. |
| 17639 | Believing a whole science is more than believing each of its propositions [Russell] |
| Full Idea: Although intrinsic obviousness is the basis of every science, it is never, in a fairly advanced science, the whole of our reason for believing any one proposition of the science. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.279) |
| 17631 | Induction is inferring premises from consequences [Russell] |
| Full Idea: The inferring of premises from consequences is the essence of induction. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.274) | |
| A reaction: So induction is just deduction in reverse? Induction is transcendental deduction? Do I deduce the premises from observing a lot of white swans? Hm. |
| 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. |
| 17633 | The law of gravity has many consequences beyond its grounding observations [Russell] |
| Full Idea: The law of gravitation leads to many consequences which could not be discovered merely from the apparent motions of the heavenly bodies. | |
| From: Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.275) |