29 ideas
| 13733 | Frege considered definite descriptions to be genuine singular terms [Frege, by Fitting/Mendelsohn] |
| Full Idea: Frege (1893) considered a definite description to be a genuine singular term (as we do), so that a sentence like 'The present King of France is bald' would have the same logical form as 'Harry Truman is bald'. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by M Fitting/R Mendelsohn - First-Order Modal Logic | |
| A reaction: The difficulty is what the term refers to, and they embrace a degree of Meinongianism - that is that non-existent objects can still have properties attributed to them, and so can be allowed some sort of 'existence'. |
| 9874 | Contradiction arises from Frege's substitutional account of second-order quantification [Dummett on Frege] |
| Full Idea: The contradiction in Frege's system is due to the presence of second-order quantification, ..and Frege's explanation of the second-order quantifier, unlike that which he provides for the first-order one, appears to be substitutional rather than objectual. | |
| From: comment on Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], §25) by Michael Dummett - Frege philosophy of mathematics Ch.17 | |
| A reaction: In Idea 9871 Dummett adds the further point that Frege lacks a clear notion of the domain of quantification. At this stage I don't fully understand this idea, but it is clearly of significance, so I will return to it. |
| 18252 | Real numbers are ratios of quantities, such as lengths or masses [Frege] |
| Full Idea: If 'number' is the referent of a numerical symbol, a real number is the same as a ratio of quantities. ...A length can have to another length the same ratio as a mass to another mass. | |
| From: Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], III.1.73), quoted by Michael Dummett - Frege philosophy of mathematics 21 'Frege's' | |
| A reaction: This is part of a critique of Cantor and the Cauchy series approach. Interesting that Frege, who is in the platonist camp, is keen to connect the real numbers with natural phenomena. He is always keen to keep touch with the application of mathematics. |
| 18271 | We can't prove everything, but we can spell out the unproved, so that foundations are clear [Frege] |
| Full Idea: It cannot be demanded that everything be proved, because that is impossible; but we can require that all propositions used without proof be expressly declared as such, so that we can see distinctly what the whole structure rests upon. | |
| From: Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], p.2), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 7 'What' |
| 10623 | Frege defined number in terms of extensions of concepts, but needed Basic Law V to explain extensions [Frege, by Hale/Wright] |
| Full Idea: Frege opts for his famous definition of numbers in terms of extensions of the concept 'equal to the concept F', but he then (in 'Grundgesetze') needs a theory of extensions or classes, which he provided by means of Basic Law V. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by B Hale / C Wright - Intro to 'The Reason's Proper Study' §1 |
| 9975 | Frege ignored Cantor's warning that a cardinal set is not just a concept-extension [Tait on Frege] |
| Full Idea: Cantor pointed out explicitly to Frege that it is a mistake to take the notion of a set (i.e. of that which has a cardinal number) to simply mean the extension of a concept. ...Frege's later assumption of this was an act of recklessness. | |
| From: comment on Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by William W. Tait - Frege versus Cantor and Dedekind III | |
| A reaction: ['recklessness' is on p.61] Tait has no sympathy with the image of Frege as an intellectual martyr. Frege had insufficient respect for a great genius. Cantor, crucially, understood infinity much better than Frege. |
| 18165 | My Basic Law V is a law of pure logic [Frege] |
| Full Idea: I hold that my Basic Law V is a law of pure logic. | |
| From: Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], p.4), quoted by Penelope Maddy - Naturalism in Mathematics I.1 | |
| A reaction: This is, of course, the notorious law which fell foul of Russell's Paradox. It is said to be pure logic, even though it refers to things that are F and things that are G. |
| 14703 | Superficial necessity is true in all worlds; deep necessity is thus true, no matter which world is actual [Schroeter] |
| Full Idea: If we have a 'fixedly' operator F, then a sentence is fixedly actually true if it is true no matter which world is designated as actual (which 'he actually won in 2008' fails to be). Maybe '□' is superficial necessity, and FA is 'deep' necessity. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.2.2) | |
| A reaction: Gareth Evans distinguishes 'deep' from 'superficial' necessity. Humberstone and others introduced 'F'. Presumably FA is deeper because it has to pass a tougher test. |
| 14714 | Contradictory claims about a necessary god both seem apriori coherent [Schroeter] |
| Full Idea: It seems apriori coherent that there could be a necessarily existing god, and that there could be no such god - but they can't both be true. Other examples include unprovable mathematical necessities | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.4) |
| 14704 | 2D semantics gives us apriori knowledge of our own meanings [Schroeter] |
| Full Idea: Generalized 2D semantics is meant to vindicate the traditional idea that we have apriori access to our own meanings through armchair reflection. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.1) | |
| A reaction: The idea is to split meaning in two, so that we know one part of it a priori. It is an unfashionably internalist view of meaning (which doesn't make it wrong!). |
| 1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
| Full Idea: I regard you all as relatives - by nature, not by convention. By nature like is akin to like, but convention is a tyrant over humankind and often constrains people to act contrary to nature. | |
| From: Hippias (fragments/reports [c.430 BCE]), quoted by Plato - Protagoras 337c8 |
| 14706 | Your view of water depends on whether you start from the actual Earth or its counterfactual Twin [Schroeter] |
| Full Idea: Your verdicts about whether the stuff on Twin Earth counts as water depends on whether you think of Twin Earth as a hypothesis about your actual environment or as a purely counterfactual possibility. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.2.3) | |
| A reaction: This is the 'two-dimensional semantics' approach to the Twin Earth problem, which splits meaning into two components. Whether you start from the actual world or from Twin Earth, you will rigidly designate the local wet stuff as 'water'. |
| 14711 | Rationalists say knowing an expression is identifying its extension using an internal cognitive state [Schroeter] |
| Full Idea: In rationalist views of meaning, based on the 'golden triangle', to be competent with an expression is to be in an internal cognitive state that puts one in a position to identify its extension in any possible world based only on apriori reflection. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.1) | |
| A reaction: This looks like a proper fight-back against modern rampant externalism about meaning. All my intuitions are with internalism, which I think points to a more coherent overall philosophy. Well done, David Chalmers! Even if he is wrong. |
| 9190 | A concept is a function mapping objects onto truth-values, if they fall under the concept [Frege, by Dummett] |
| Full Idea: In later Frege, a concept could be taken as a particular case of a function, mapping every object on to one of the truth-values (T or F), according as to whether, as we should ordinarily say, that object fell under the concept or not. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by Michael Dummett - The Philosophy of Mathematics 3.5 | |
| A reaction: As so often in these attempts at explanation, this sounds circular. You can't decide whether an object truly falls under a concept, if you haven't already got the concept. His troubles all arise (I say) because he scorns abstractionist accounts. |
| 13665 | Frege took the study of concepts to be part of logic [Frege, by Shapiro] |
| Full Idea: Frege took the study of concepts and their extensions to be within logic. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by Stewart Shapiro - Foundations without Foundationalism 7.1 | |
| A reaction: This is part of the plan to make logic a universal language (see Idea 13664). I disagree with this, and with the general logicist view of the position of logic. The logical approach thins concepts out. See Deleuze/Guattari's horror at this. |
| 14717 | Internalist meaning is about understanding; externalist meaning is about embedding in a situation [Schroeter] |
| Full Idea: Internalists take the notion of meaning to capture an aspect of an individual's current state of understanding, while externalists take the notion of meaning to reflect how an individual is embedded within her social and physical environment. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.4.3) | |
| A reaction: This idea also occurs in discussions of concepts (filed here under 'Thought'). |
| 14720 | Semantic theory assigns meanings to expressions, and metasemantics explains how this works [Schroeter] |
| Full Idea: A semantic theory assigns semantic values (meanings) to particular expressions of the language. In contrast, a metasemantic theory explains why expressions have those semantic values, appealing to facts about speakers and communities. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 3.4) | |
| A reaction: Presumably some people only want the metasemantic version. I assume that the two are entangled, but I would vote for both. |
| 14695 | Semantic theories show how truth of sentences depends on rules for interpreting and joining their parts [Schroeter] |
| Full Idea: Semantic theories explain how the truth or falsity of whole sentences depends on the meanings of their parts by stating rules governing the interpretation of subsentential expressions and their modes of combination. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: Somehow it looks as if the mystery of the whole business will still be missing if this project is ever successfully completed. Also one suspects that such a theory would be a fiction, rather than a description of actuality, which is too complex. |
| 14696 | Simple semantics assigns extensions to names and to predicates [Schroeter] |
| Full Idea: The simplest semantic frameworks assign extensions as semantic values of particular expressions. The extension of a name is the thing, of 'cool' is the set of cool things, and sets of ordered pairs for 2-place predicates. The sentence has T or F. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: The immediate well-known problem is different predicates with the same extensions, such as 'renate' and 'cordate'. Possible worlds semantics is supposed to be an improvement to cover this, and to give a semantics for modal talk as well. Sounds good. |
| 14697 | 'Federer' and 'best tennis player' can't mean the same, despite having the same extension [Schroeter] |
| Full Idea: A simple extensional semantics will assign the same semantic value to 'Roger Federer' and 'world's best tennis player', but they clearly differ in meaning, and if events had unfolded differently they would pick out different people. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: You would think that this would be too obvious to need pointing out, but it is clearly a view that had a lot of popularity before the arrival of possible worlds. |
| 14698 | Possible worlds semantics uses 'intensions' - functions which assign extensions at each world [Schroeter] |
| Full Idea: In standard possible worlds semantics, the semantic value of an expression is an 'intension', a function that assigns an extension to the expression 'at' every possible world. ...It keeps track of the 'modal profiles' of objects, kinds and properties. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: Personally I just don't buy a semantics which is entirely based on extensions, even if this has sorted out some more obvious problems of extensionality. When I say someone is 'my hero', I don't just mean to pick out a particular person. |
| 14699 | Possible worlds make 'I' and that person's name synonymous, but they have different meanings [Schroeter] |
| Full Idea: In standard possible worlds semantics the semantic value of Hllary Clinton's utterance of 'I' will be the same as her utterance of 'Hillary Clinton'. But clearly the English word 'I' is not synonymous with the name 'Hillary Clinton'. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.1) | |
| A reaction: This problem was spotted by Kaplan, and it has been a chief motivator for the creation of two-dimensional semantics, which some people have then extended into a complete semantic theory. No purely extensional semantics can be right. |
| 14709 | Possible worlds semantics implies a constitutive connection between meanings and modal claims [Schroeter] |
| Full Idea: In standard possible world semantics an expression's intension reflects the modal profile of an object, kind or property, which would establish an important constitutive connection between meanings and modal claims. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.1) | |
| A reaction: The central question becomes 'do you need to know a thing's modal profile in order to have a decent understanding of it?', but if you express it that way (my way), then what counts as 'decent' will be relative to all sorts of things. |
| 14719 | In the possible worlds account all necessary truths are same (because they all map to the True) [Schroeter] |
| Full Idea: A problem for a standard possible worlds analysis is that all necessary truths have precisely the same content (the function mapping every world to the True). Hesperus=Phosphorus has the same content as Hesperus=Hesperus-and-2+2=4. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 3.3) | |
| A reaction: If this is supposed to be a theory of meaning then it has gone very badly wrong indeed. Has modern semantics taken a wrong turning somewhere? Two-dimensionalism is meant to address some of these problems. |
| 14701 | Array worlds along the horizontal, and contexts (world,person,time) along the vertical [Schroeter] |
| Full Idea: In a two-dimensional matrix we array possible circumstances of evaluation (worlds) along the horizontal axis, and possible contexts of utterance (world, person, time) along the vertical axis. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.1.2) | |
| A reaction: This is due to Stalnaker 1978, and is clearest in operation when applied to an indexical such as 'I' in 'I am President'. 'I' is a rigid designator, but depends on context. The grid is filled in with T or F for each utterance in each world. |
| 14702 | If we introduce 'actually' into modal talk, we need possible worlds twice to express this [Schroeter] |
| Full Idea: At first glance necessity and possibility can be fully expressed by quantifying over all possible worlds, but this cannot capture 'Possibly everything actually red is also shiny'. This needs a double-indexed framework, with worlds playing two roles. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 1.2.1) | |
| A reaction: She points out that this also applies to tense logic, for the notion of 'now'. The point is that we not only need a set of possible worlds, but we also need a procedure (the 'Actuality' operator A or @) for picking out one of the worlds as special. |
| 14705 | Do we know apriori how we refer to names and natural kinds, but their modal profiles only a posteriori? [Schroeter] |
| Full Idea: Perhaps our best way of understanding names and natural kind terms is that we have apriori access to currently associated reference-fixing criterion, but only a posteriori access to the associated modal profile. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.1) | |
| A reaction: This is the 'generalized' view of 2D semantics (covering everything, not just modals and indexicals). I know apriori what something is, but only study will reveal its possibilities. The actual world is easy to talk about, but possible worlds are harder. |
| 14715 | 2D fans defend it for conceptual analysis, for meaning, and for internalist reference [Schroeter] |
| Full Idea: Supporters of generalized two-dimensional semantics agree to defend apriori conceptual analysis in metaphysics, and that 2D captures meaning and not just belief-patterns, and it gives a broadly internalist approach to reference determination. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.3.4) | |
| A reaction: I'm not sure I can evaluate this, but I sort of like conceptual analysis, and the concept of meaning, and fairly internalist views of reference, so I am ripe for the picking. |
| 14716 | 2D semantics can't respond to contingent apriori claims, since there is no single proposition involved [Schroeter] |
| Full Idea: It is objected to 2D semantics that it cannot explain Kripke's cases of contingent apriori truths, for there is no single proposition (construed as a set of possible worlds) that is both apriori and contingent. | |
| From: Laura Schroeter (Two-Dimensional Semantics [2010], 2.4.2) | |
| A reaction: This sounds like a rather large objection to the whole 2D plan, if it implies that when we say something there is no single proposition that is being expressed. |