26 ideas
| 16123 | Whenever you perceive a community of things, you should also hunt out differences in the group [Plato] |
| Full Idea: The rule is that when one perceives first the community between the members of a group of many things, one should not desist until one sees in it all those differences that are located in classes. | |
| From: Plato (The Statesman [c.356 BCE], 285b) | |
| A reaction: He goes on to recommend the opposite as well - see community even when there appears to be nothing but differences. I take this to be analysis, just as much as modern linguistic approaches are. Analyse the world, not language. |
| 16125 | To reveal a nature, divide down, and strip away what it has in common with other things [Plato] |
| Full Idea: Let's take the kind posited and cut it in two, .then follow the righthand part of what we've cut, and hold onto things that the sophist is associated with until we strip away everything he has in common with other things, then display his peculiar nature. | |
| From: Plato (The Statesman [c.356 BCE], 264e) | |
| A reaction: This seems to be close to Aristotle's account of definition, when he is trying to get at what-it-is-to-be some thing. But if you strip away everything the definiendum has in common with other things, will anything remain? |
| 16124 | No one wants to define 'weaving' just for the sake of weaving [Plato] |
| Full Idea: I don't suppose that anyone with any sense would want to hunt down the definition of 'weaving' for the sake of weaving itself. | |
| From: Plato (The Statesman [c.356 BCE], 285d) | |
| A reaction: The point seems to be that the definition brings out the connections between weaving and other activities and objects, thus enlarging our understanding. |
| 18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
| Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1) | |
| A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark. |
| 18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
| Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise. |
| 7760 | Russell only uses descriptions attributively, and Strawson only referentially [Donnellan, by Lycan] |
| Full Idea: Donnellan objects that Russell's theory of definite descriptions overlooks the referential use (Russell writes as if all descriptions are used attributively), and that Strawson assumes they are all used referentially, to draw attention to things. | |
| From: report of Keith Donnellan (Reference and Definite Descriptions [1966]) by William Lycan - Philosophy of Language Ch.1 | |
| A reaction: This seems like a nice little success for analytical philosophy - clarifying a horrible mess by making a simple distinction that leaves everyone happy. |
| 5811 | A definite description can have a non-referential use [Donnellan] |
| Full Idea: A definite description may also be used non-referentially, even as it occurs in one and the same sentence. | |
| From: Keith Donnellan (Reference and Definite Descriptions [1966], §I) | |
| A reaction: Donnellan says we have to know about the particular occasion on which the description is used, as in itself it will not achieve reference. "Will the last person out switch off the lights" achieves its reference at the end of each day. |
| 5812 | Definite descriptions are 'attributive' if they say something about x, and 'referential' if they pick x out [Donnellan] |
| Full Idea: A speaker who uses a definite description 'attributively' in an assertion states something about whoever or whatever is the so-and-so; a speaker who uses it 'referentially' enables his audience to pick out whom or what he is talking about. | |
| From: Keith Donnellan (Reference and Definite Descriptions [1966], §III) | |
| A reaction: "Smith's murderer is insane" exemplifies the first use before he is caught, and the second use afterwards. The gist is that reference is not a purely linguistic activity, but is closer to pointing at something. This seems right. |
| 5814 | 'The x is F' only presumes that x exists; it does not actually entail the existence [Donnellan] |
| Full Idea: For Russell there is a logical entailment: 'the x is F' entails 'there exists one and only one x'. Whether or not this is true of the attributive use of definite descriptions, it does not seem true of the referential use. The existence is a presumption. | |
| From: Keith Donnellan (Reference and Definite Descriptions [1966], §VI) | |
| A reaction: Can we say 'x does not exist, but x is F'? Strictly, that sounds to me more like a contradiction than a surprising rejection of a presumption. However, 'Father Xmas does not exist, but he has a red coat'. |
| 18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
| Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea. |
| 18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
| Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting. |
| 18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
| Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory. |
| 18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
| Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions. |
| 18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
| Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular). |
| 18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
| Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds. |
| 18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
| Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5) | |
| A reaction: They accept lots of successes in modelling necessity and time. |
| 5961 | The soul gets its goodness from god, and its evil from previous existence. [Plato] |
| Full Idea: From its composer the soul possesses all beautiful things, but from its former condition, everything that proves to be harsh and unjust in heaven. | |
| From: Plato (The Statesman [c.356 BCE], 273b) | |
| A reaction: A neat move to explain the origins of evil (or rather, to shift the problem of evil to a long long way from here). This view presumably traces back to the views of Empedocles on good and evil. Can the soul acquire evil in its current existence? |
| 10435 | A definite description 'the F' is referential if the speaker could thereby be referring to something not-F [Donnellan, by Sainsbury] |
| Full Idea: Donnellan argued that we could recognize a referential use of a definite description 'the F' by the fact that the speaker could thereby refer to something which is not F. | |
| From: report of Keith Donnellan (Reference and Definite Descriptions [1966]) by Mark Sainsbury - The Essence of Reference 18.5 | |
| A reaction: If the expression employed achieved reference whether the speaker wanted it to or not, it would certainly look as if the expression was inherently referring. |
| 10451 | Donnellan is unclear whether the referential-attributive distinction is semantic or pragmatic [Bach on Donnellan] |
| Full Idea: Donnellan seems to be unsure whether to regard his referential-attributive distinction as indicating a semantic ambiguity or merely a pragmatic one. | |
| From: comment on Keith Donnellan (Reference and Definite Descriptions [1966]) by Kent Bach - What Does It Take to Refer? 22.2 L1 | |
| A reaction: I vote for pragmatic. In a single brief conversation a definite description could start as attributive and end as referential, but it seems unlikely that its semantics changed in mid-paragraph. |
| 5813 | A description can successfully refer, even if its application to the subject is not believed [Donnellan] |
| Full Idea: If I think the king is a usurper, "Is the king in his counting house?" succeeds in referring to the right man, even though I do not believe that he fits the description. | |
| From: Keith Donnellan (Reference and Definite Descriptions [1966], §IV) | |
| A reaction: This seems undeniable. If I point at someone, I can refer successfully with almost any description. "Oy! Adolf! Get me a drink!" Reference is an essential aspect of language, and it is not entirely linguistic. |
| 5815 | Whether a definite description is referential or attributive depends on the speaker's intention [Donnellan] |
| Full Idea: Whether or not a definite description is used referentially or attributively is a function of the speaker's intentions in a particular case. | |
| From: Keith Donnellan (Reference and Definite Descriptions [1966], §VII) | |
| A reaction: Donnellan's distinction, and his claim here, seem to me right. However words on a notice could refer on one occasion, and just describe on another. "Anyone entering this cage is mad". |
| 283 | The question of whether or not to persuade comes before the science of persuasion [Plato] |
| Full Idea: The science of whether one must persuade or not must rule over the science capable of persuading. | |
| From: Plato (The Statesman [c.356 BCE], 304c) | |
| A reaction: Plato probably thinks that reason has to be top of the pyramid, but there is always the Nietzschean/romantic question of why we should place such a value on what is rational. |
| 282 | Non-physical beauty can only be shown clearly by speech [Plato] |
| Full Idea: The bodiless things, being the most beautiful and the greatest, are only shown with clarity by speech and nothing else. | |
| From: Plato (The Statesman [c.356 BCE], 286a) | |
| A reaction: Unfortunately this will be true of warped and ugly ideas as well. |
| 281 | The arts produce good and beautiful things by preserving the mean [Plato] |
| Full Idea: It is by preserving the mean that arts produce everything that is good and beautiful. | |
| From: Plato (The Statesman [c.356 BCE], 284b) |
| 22559 | Democracy is the worst of good constitutions, but the best of bad constitutions [Plato, by Aristotle] |
| Full Idea: Plato judged that when the constitution is decent, democracy is the worst of them, but when they are bad it is the best. | |
| From: report of Plato (The Statesman [c.356 BCE], 302e) by Aristotle - Politics 1289b07 | |
| A reaction: Aristotle denies that a good oligarchy is superior. What of technocracy? The challenge is to set up institutions which ensure the health of the democracy. The big modern problem is populists who lie. |
| 279 | Only divine things can always stay the same, and bodies are not like that [Plato] |
| Full Idea: It is fitting for only the most divine things of all to be always the same and in the same state and in the same respects, and the nature of body is not of this ordering. | |
| From: Plato (The Statesman [c.356 BCE], 269b) |