41 ideas
| 8092 | Logic was merely a branch of rhetoric until the scientific 17th century [Devlin] |
| Full Idea: Until the rise of what we call the scientific method in the seventeenth century, logic was regarded largely as one aspect of rhetoric - a study of how one person't argument could convince another. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch.11) | |
| A reaction: This may well give the main reason why the Greeks invented logic in the first place. Aristotle wrote a book on rhetoric, and that was where the money was. Leibniz is clearly a key figure in the change of attitude. |
| 21021 | Keep premises as weak as possible, to avoid controversial difficulties [Nussbaum] |
| Full Idea: One should always choose the weakest premises from which one's conclusion follows, rather than saddling the theory with thicker or more controversial premises. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 8) | |
| A reaction: I like this because it connects the rather vague Ockham's Razor to the logical concept of Thinning. The key point is that a thinner set of premises that prove something will be more persuasive, because critics may reject premises instead of conclusion. |
| 8081 | 'No councillors are bankers' and 'All bankers are athletes' implies 'Some athletes are not councillors' [Devlin] |
| Full Idea: Most people find it hard to find any conclusion that fits the following premises: 'No councillors are bankers', and 'All bankers are athletes'. There is a valid conclusion ('Some athletes are not councillors') but it takes quite an effort to find it. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 2) | |
| A reaction: A nice illustration of the fact that syllogistic logic is by no means automatic and straightforward. There is a mechanical procedure, but a lot of intuition and common sense is also needed. |
| 8085 | Modern propositional inference replaces Aristotle's 19 syllogisms with modus ponens [Devlin] |
| Full Idea: Where Aristotle had 19 different inference rules (his valid syllogisms), modern propositional logic carries out deductions using just one rule of inference: modus ponens. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 4) | |
| A reaction: At first glance it sounds as if Aristotle's guidelines might be more useful than the modern one, since he tells you something definite and what implies what, where modus ponens just seems to define the word 'implies'. |
| 8086 | Predicate logic retains the axioms of propositional logic [Devlin] |
| Full Idea: Since predicate logic merely extends propositional logic, all the axioms of propositional logic are axioms of predicate logic. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 4) | |
| A reaction: See Idea 7798 for the axioms. |
| 8091 | Situation theory is logic that takes account of context [Devlin] |
| Full Idea: In many respects, situation theory is an extension of classical logic that takes account of context. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 8) | |
| A reaction: John Barwise is cited as the parent of this movement. Many examples show that logical form is very hard to pin down, because word-meaning depends on context (e.g. 'several crumbs' differs from 'several mountains'). |
| 8087 | Golden ages: 1900-1960 for pure logic, and 1950-1985 for applied logic [Devlin] |
| Full Idea: The period from 1900 to about 1960 could be described as the golden age of 'pure' logic, and 1950 to 1985 the golden age of 'applied' logic (e.g. applied to everyday reasoning, and to theories of language). | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 4) | |
| A reaction: Why do we always find that we have just missed the Golden Age? However this supports the uneasy feeling that the golden age for all advances in human knowledge is just coming to an end. Biology, including the brain, is the last frontier. |
| 8089 | Montague's intensional logic incorporated the notion of meaning [Devlin] |
| Full Idea: Montague's intensional logic was the first really successful attempt to develop a mathematical framework that incorporates the notion of meaning. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 8) | |
| A reaction: Previous logics, led by Tarski, had flourished by sharply dividing meaning from syntax, and concentrating on the latter. |
| 8082 | Where a conditional is purely formal, an implication implies a link between premise and conclusion [Devlin] |
| Full Idea: Implication involves some form of link or causality between the antecedent and the consequent of an if-then; normally it says that the conclusion is a consequence of the premise (where conditionals are just defined by 'true' and 'false'). | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 2) | |
| A reaction: This distinction is a key one when discussing 'If-then' sentences. Some are merely formal conditionals, but others make real claims about where you can get to from where you are. |
| 8072 | Sentences of apparent identical form can have different contextual meanings [Devlin] |
| Full Idea: "Safety goggles must be worn in the building" is clear enough, but "dogs must always be carried on the escalator" doesn't require us to head off in search of a dog. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 1) | |
| A reaction: A nice illustration of how the requirements of logical form will often take us beyond the strict and literal meaning of a sentence, into context, tone, allusion and subjective aspects. |
| 8075 | Space and time are atomic in the arrow, and divisible in the tortoise [Devlin] |
| Full Idea: The arrow paradox starts with the assumption that space and time are atomic; the tortoise starts with the opposite assumption that space and time are infinitely divisible. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 2) | |
| A reaction: Aquinas similarly covers all options (the cosmos has a beginning, or no beginning). The nature of movement in a space which involves quantum leaps remains metaphysically puzzling. Where is a particle at half of the Planck time? |
| 8088 | People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin] |
| Full Idea: The Hopi time myth does not appear to have been stopped for a moment by the fact that Whorf himself subsequently wrote that the Hopi language does indeed have words for past, present, and future | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 5) | |
| A reaction: Arguments for relativism based on the Hopi seem now to be thoroughly discredited. Sensible people never believed them in the first place. |
| 8073 | How do we parse 'time flies like an arrow' and 'fruit flies like an apple'? [Devlin] |
| Full Idea: How do people identify subject and verb in the sentences "time flies like an arrow" and "fruit flies like an apple"? | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 1) | |
| A reaction: A nice illustration of the fact that even if we have an innate syntax mechanism, it won't work without some semantics, and some experience of the environmental context of utterances. |
| 8076 | The distinction between sentences and abstract propositions is crucial in logic [Devlin] |
| Full Idea: The distinction between sentences and the abstract propositions that they express is one of the key ideas of logic. A logical argument consists of propositions, assembled together in a systematic fashion. | |
| From: Keith Devlin (Goodbye Descartes [1997], Ch. 2) | |
| A reaction: He may claim that arguments consist of abstract propositions, but they always get expressed in sentences. However, the whole idea of logical form implies the existence of propositions - there is something which a messy sentence 'really' says. |
| 21007 | Storytelling is never neutral; some features of the world must be emphasised [Nussbaum] |
| Full Idea: Storytelling is never neutral; the narrator always directs attention to some features of the world rather than others. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 1) | |
| A reaction: The audience would be a bit stupid if it insisted on neutrality. |
| 20400 | Intentions either succeed or fail, so external evidence for them is always irrelevant [Wimsatt/Beardsley, by Davies,S] |
| Full Idea: Wimsatt and Beardsley claimed that either the intention succeeded, so one does not need to look outside the work for its meaning, or the intention failed, so external evidence does not help. | |
| From: report of W Wimsatt/W Beardsley (The Intentional Fallacy [1946]) by Stephen Davies - The Philosophy of Art (2nd ed) 5.3 | |
| A reaction: Actually, the external evidence may tell you much more clearly and accurately what the intention was than the work itself does. The best example may be the title of the work, which is presumably outside the work. |
| 7266 | The author's intentions are irrelevant to the judgement of a work's success [Wimsatt/Beardsley] |
| Full Idea: The design or intention of the author is neither available nor desirable as a standard for judging the success of a work of literary art. | |
| From: W Wimsatt/W Beardsley (The Intentional Fallacy [1946], §I) | |
| A reaction: This famous proposal may have been misunderstood. Note that it is a comment about judging the work, not about understanding it. The idea allows for a work being much more successful than the author's humble intentions (e.g. Pepys). |
| 7267 | Poetry, unlike messages, can be successful without communicating intentions [Wimsatt/Beardsley] |
| Full Idea: Poetry differs from practical messages, which are successful if and only if we correctly infer the intention. | |
| From: W Wimsatt/W Beardsley (The Intentional Fallacy [1946], §I) | |
| A reaction: I am not convinced by this claim. It is plausible that a work does much more than it intends (Astaire said he danced "to make a buck"), but it is rather odd to rate very highly a work of which you have missed the point. |
| 7268 | The thoughts of a poem should be imputed to the dramatic speaker, and hardly at all to the poet [Wimsatt/Beardsley] |
| Full Idea: We ought to impute the thoughts and attitudes of the poem immediately to the dramatic speaker, and if to the author at all, only by an act of biographical inference. | |
| From: W Wimsatt/W Beardsley (The Intentional Fallacy [1946], §I) | |
| A reaction: Wrong. If in Browning's "My Last Duchess" (say), we only inferred the mind of the speaker (and his Duchess), and took no interest in Browning's view of things, we would miss the point. We might end up respecting the Duke, which would be daft. |
| 7269 | The intentional fallacy is a romantic one [Wimsatt/Beardsley] |
| Full Idea: The intentional fallacy is a romantic one. | |
| From: W Wimsatt/W Beardsley (The Intentional Fallacy [1946], §II) | |
| A reaction: Wrong. Even with those most famous of anonymous artists, the architects and carvers of medieval cathedrals, without some discernment of the purpose you won't get it. The Taj Mahal is a love letter, not a potential ice cream parlour. |
| 7271 | Biography can reveal meanings and dramatic character, as well as possible intentions [Wimsatt/Beardsley] |
| Full Idea: The use of biographical evidence need not involve intentionalism, because while it may be evidence of what the author intended, it may also be evidence of the meaning of his words and the dramatic character of his utterance. | |
| From: W Wimsatt/W Beardsley (The Intentional Fallacy [1946], §IV) | |
| A reaction: I am very keen to penetrate the author's intentions, but I have always be doubtful about the use of biography as a means to achieve this. Most of the effort to infer intentions must come from a study of the work itself, not introductions, letters etc. |
| 22688 | The Aristotelian idea that choices can be perceived needs literary texts to expound it [Nussbaum] |
| Full Idea: To show forth the Aristotelian claim that 'the decision rests with perception', we need - either side by side with a philosophical outline or inside it - literary texts which display the complexity, indeterminacy, and sheer difficulty of moral choice. | |
| From: Martha Nussbaum (The Golden Bowl, and Lit as Moral Philosophy [1983], II) | |
| A reaction: Berys Gaut observes that this depends on a particularist view of moral choice (usually seen as Aristotelian), with little interest in principles. |
| 21836 | Philosophers after Aristotle endorsed the medical analogy for eudaimonia [Nussbaum, by Flanagan] |
| Full Idea: Nussbaum says the post-Aristotelian philosophers did much more than simply advancing and refining Aristotle's ethics. They advanced eudaimonics by explicitly endorsing the medical analogy. | |
| From: report of Martha Nussbaum (The Therapy of Desire [1994]) by Owen Flanagan - The Really Hard Problem 4 'Eudaimoncs' | |
| A reaction: Since Aristotle is all about the successful functioning of the psuche, this idea is obviously implicit in his original texts. It needs a positive concept of mental health, and not a mere absence of mental illness. See the Mindapples campaign. |
| 21025 | Particularism gives no guidance for the future [Nussbaum] |
| Full Idea: Situation ethics offers no guidance for the future. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 8) | |
| A reaction: Not sure if Situation Ethics is the same as Particularism. Jonathan Danby famously champions the latter. |
| 21026 | Compassion is unreliable, because it favours people close to us [Nussbaum] |
| Full Idea: Daniel Batson's important research has shown us that compassion is not reliable on its own, because it can easily give priority to people close to the self. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 8) | |
| A reaction: In Britain animal charities receive vastly more money than children's charities, presumably for this very reason. Kittens - you've got to hate them. |
| 21019 | Social contracts assume equal powers among the participants [Nussbaum] |
| Full Idea: All contract theories, including Rawls's, assume a rough equality of physical and mental power among the participants. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 4) |
| 21011 | We shouldn't focus on actual preferences, which may be distorted by injustices [Nussbaum] |
| Full Idea: When society puts things out of reach for people, they typically learn not to want those things. ..By defining the social goal in terms of satisfaction of actual preferences, utilitarian approaches often reinforce the status quo, which may be very unjust. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 3) | |
| A reaction: Maximising happiness is potentially very paternalistic, whereas preference satisfaction is not, which aligns utilitarianism better with liberalism. It is notorious that slaves can be contented with their slavery, and battered wives can remain loyal. |
| 21008 | Liberalism does not need a comprehensive account of value [Nussbaum] |
| Full Idea: The role of political liberalism in my theory requires me to prescind from offering any comprehensive account of value. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 2) | |
| A reaction: Obviously liberalism has values, but they are the minimum ones of freedom and respect. Liberals have to tolerate some fairly ugly and miserable societies. Can liberals intervene in family life? |
| 21125 | Liberals must respect family freedom - but families are the great oppressors of women [Nussbaum] |
| Full Idea: A liberal society should give people considerable latitude to form families as they choose. …On the other hand the family …is one of the most notorious homes of sex hierarchy, denial of sexual opportunity, and sex-based violence and humiliation. | |
| From: Martha Nussbaum (Rawls and Feminism [2003], 03), quoted by Andrew Shorten - Contemporary Political Theory | |
| A reaction: The question of how the state might intervene in the family rarely seems to turn up in standard political theory. This idea shows why that is a mistake. |
| 21012 | Women are often treated like children, and not respected for their choices [Nussbaum] |
| Full Idea: Women are often treated as passive dependents, creatures to be cared for (or not), rather than as independent human beings deserving respect for their choices. In other words they are often infantilized. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 3) | |
| A reaction: Her prime example is from India, but you see the same thing in more subtle forms in the UK, especially among older people, and especially in art galleries. |
| 21015 | Negative liberty is incoherent; all liberties, to do and to be, require the prevention of interference [Nussbaum] |
| Full Idea: The very idea of 'negative liberty' ...is an incoherent idea: all liberties are positive, meaning liberties to do or to be something, which all require the inhibition of interference by others. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 3) | |
| A reaction: This rejects Isaiah Berlin's well-known claim that negative liberties are good, but positive liberties are far too dangerous. |
| 21017 | Political freedom is an incoherent project, because some freedoms limit other freedoms [Nussbaum] |
| Full Idea: It is unclear whether the idea of promoting freedom is even a coherent political project. Some freedoms limit others. The freedom of rich people to make large donations to political campaigns can limit the equal worth of the right to vote. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 4) | |
| A reaction: It is not just American right-wingers who over-emphasise 'freedom'. French philosophy seems to be riddled with the same thing. |
| 21016 | Political and civil rights are not separate from economic and social rights [Nussbaum] |
| Full Idea: My approach rejects the distinction, common in the human rights movement, between 'first-generation rights' (political and civil) and 'second-generation rights' (economic and social). The second group are preconditions of the first group. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 3) | |
| A reaction: [last sentence compressed] This sounds like the sort of point Marx argued for. Nowadays it is feminists who make this point most strongly. |
| 21009 | Capabilities: Life, Health, Safety, Mental life, Love, Planning, Joining in, Nature, Play, Control [Nussbaum, by PG] |
| Full Idea: Ten Capabilities: Life (decent), Health (reproduction, shelter), Safety, Mental life (with education), Love (relationships), Planning (with free beliefs), Joining in (and non-discrimination), Nature (relations to), Play, Control (politics and property). | |
| From: report of Martha Nussbaum (Creating Capabilities [2011], 2) by PG - Db (ideas) | |
| A reaction: She gives her crucial list in rather wordy form. To have impact it needs to be reduced to brief simple slogans. |
| 21010 | Justice requires that the ten main capabilities of people are reasonably enabled [Nussbaum] |
| Full Idea: The basic claim of my account of social justice is this: respect for human dignity requires that citizens be placed above an ample (specified) threshold of capability in all ten of the areas. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 2) | |
| A reaction: [The capabilities are given, briefly, in Idea 21009] The one word that bothers me here is 'dignity'. It is very vague, and can, I think, be reduced to much clearer and more obvious concepts. A person lacks dignity when they vomit, in ordinary usage. |
| 21013 | Capabilities are grounded in bare humanity and agency; qualifying as rational is not needed [Nussbaum] |
| Full Idea: The capabilities approach grounds rights claims in bare human birth and minimal agency, not in rationality or any other specific property, something that permits it to recognise the equal human rights of people with cognitive disabilities. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 3) | |
| A reaction: She says elsewhere that she also sees animals as included in the capabilities approach. This is a rejection of the Kantian grounds for rights (by a well-known Aristotelian). |
| 21014 | Rights are not just barriers against state interference; governments must affirm capabilities of citizens [Nussbaum] |
| Full Idea: A prominent idea, common in the U.S., sees rights as barriers against interfering state action. ...The Capabilities Approach, by contrast, insists that all entitlements involve an affirmative task for government, to actively support capabilities. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 3) | |
| A reaction: This makes her approach very left wing, by U.S. standards, because it needs higher taxation and a degree of government paternalism. Her approach strikes me as an excellent agenda for a fairly interventionist European liberal party. |
| 21020 | Any establishment belief system is incompatible with full respect for all citizens [Nussbaum] |
| Full Idea: The idea of equal respect is difficult or impossible to render compatible with a religious establishment, even one that is benign and noncoercive. Any established church (or government secularism) denigrates nonbelievers, by stating they are an out-group. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 4) | |
| A reaction: This sort of applies to membership of anything. She is sort of right, but there is no reason in principle why full respect should not be accorded to any out-group. |
| 21023 | We should respect animals in the way that we respect the animal nature in humans [Nussbaum] |
| Full Idea: If we show respect to our own animal natures, it is simply inconsistent, and a kind of vicious self-promoting of a sort to which Kantians are especially opposed, to refuse the same respect to our fellow creatures. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 8) | |
| A reaction: Nussbaum says Kant is hopeless on animals, but Christine Korsgaard offers this Kantian approach that demands genuine respect for animals, even though they are not considered rational. Nussbaum says animals are agents. Did Kant respect our animality? |
| 21024 | It may be no harm to kill an animal which cannot plan for its future [Nussbaum] |
| Full Idea: The painless killing of an animal of a species that does not make plans extending into the future may not be a harm: this depends on how we think about the harm of death. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 8) | |
| A reaction: Very old human beings may have no plans for the future. I, on the other hand, have got lots and lots of plans. Definitely. No one can specify the harm of death. How can it be distinguished from the harm of not being born? |
| 21022 | The Capabilities Approach sees animals as agents, not just as having feelings [Nussbaum] |
| Full Idea: The Capabilities Approach sees animals as agents, not as receptacles of pleasure or pain. | |
| From: Martha Nussbaum (Creating Capabilities [2011], 8) | |
| A reaction: This is in opposition to the utilitarian view. The key consequence is that animals can be victims of injustice, as well as of cruelty. Nice. |