44 ideas
| 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. |
| 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. |
| 7557 | To solve Zeno's paradox, reject the axiom that the whole has more terms than the parts [Russell] |
| Full Idea: Presumably Zeno appealed to the axiom that the whole has more terms than the parts; so if Achilles were to overtake the tortoise, he would have been in more places than the tortoise, which he can't be; but the conclusion is absurd, so reject the axiom. | |
| From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.89) | |
| A reaction: The point is that the axiom is normally acceptable (a statue contains more particles than the arm of the statue), but it breaks down when discussing infinity (Idea 7556). Modern theories of infinity are needed to solve Zeno's Paradoxes. |
| 10059 | In mathematic we are ignorant of both subject-matter and truth [Russell] |
| Full Idea: Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true. | |
| From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.76) | |
| A reaction: A famous remark, though Musgrave is rather disparaging about Russell's underlying reasoning here. |
| 7556 | A collection is infinite if you can remove some terms without diminishing its number [Russell] |
| Full Idea: A collection of terms is infinite if it contains as parts other collections which have as many terms as it has; that is, you can take away some terms of the collection without diminishing its number; there are as many even numbers as numbers all together. | |
| From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.86) | |
| A reaction: He cites Dedekind and Cantor as source for these ideas. If it won't obey the rule that subtraction makes it smaller, then it clearly isn't a number, and really it should be banned from all mathematics. |
| 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. |
| 7554 | Self-evidence is often a mere will-o'-the-wisp [Russell] |
| Full Idea: Self-evidence is often a mere will-o'-the-wisp, which is sure to lead us astray if we take it as our guide. | |
| From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.78) | |
| A reaction: The sort of nice crisp remark you would expect from a good empiricist philosopher. Compare Idea 4948. However Russell qualifies it with the word 'often', and all philosophers eventually realise that you have to start somewhere. |
| 20589 | Maybe a person's true self is their second-order desires [Tuckness/Wolf] |
| Full Idea: A second-order desire is a desire about what kind of desires you want to have. ....Some philosophers have argued that we should associate a person's second-order desires with her 'true self'. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 2 'What is') | |
| A reaction: Presumably the buck stops at these second-order desires, though we might request an account of their origin. 'What sort of person do I want to be?' looks like a third-order question. I don't even want to be a saint. Self is nothing to do with desires? |
| 20583 | If maximising pleasure needs measurement, so does fulfilling desires [Tuckness/Wolf] |
| Full Idea: Just as hedonists need a way to compare pleasures, so desire fulfilment theorists need a way to compare the fulfilment of desires. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 1 'Is happiness') | |
| A reaction: A nice point. We picture desire fulfilment as just ticking it off when it is achieved, but if your desire is for a really nice house, the achievement of that can be pretty vague. |
| 20584 | Desire satisfaction as the ideal is confused, because we desire what we judge to be good [Tuckness/Wolf] |
| Full Idea: Critics of desire satisfaction theory argue that it gets things backward. We desire things because we already think they are good in some way. Desire theory puts it the other way round. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 1 'Is happiness') | |
| A reaction: Not persuasive. It looks to me as if skiing is a spendid pastime, but I have no desire to do it. More exercise would even be a good for me, but I don't desire that either. Indeed, right now I desire more cake, which is very naughty. |
| 20598 | In a democracy, which 'people' are included in the decision process? [Tuckness/Wolf] |
| Full Idea: In any democratic state, who are 'the people' who get to rule themselves? That is, who gets to participate in the public decision process, and who is excluded? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'What is') | |
| A reaction: In the modern world this may be clear-cut when a democracy gets started, but people move around so much more that every democracy is faced with new types of residents. Then there is age, criminality, mental health... |
| 20614 | People often have greater attachment to ethnic or tribal groups than to the state [Tuckness/Wolf] |
| Full Idea: Some states have a number of different ethnic or tribal groups. Often these attachments are much stronger than the attachment people feel towards the state. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 6 'Membership') | |
| A reaction: In Britain I fine people torn between attachments to the UK and to England or Wales or Scotland or NI. Attachments to football clubs are much stronger than most patriotism. Or attachment to a particular locality. Does it matter? |
| 20596 | For global justice, adopt rules without knowing which country you will inhabit [Tuckness/Wolf] |
| Full Idea: Imagine a new original position where we adopted rules for global justice without knowing which country we would inhabit. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 4 'Cosmopolitan') | |
| A reaction: Nice question. North Korea!! Rawls says it is only within a nation, because there is a co-operative enterprise going on. That is, I presume, that the choosers involved are a 'people'. See Kant's 'Perpetual Peace' for an alternative. |
| 20593 | The veil of ignorance ensures both fairness and unanimity [Tuckness/Wolf] |
| Full Idea: The veil of ignorance ensures that the original position is fair, but it also guarantees that agreement will be unanimous (which would be impossible if each person insisted that justice should match her own conception). | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 4 'Original') | |
| A reaction: Not clear about this. If I choose very cautiously, but others choose very riskily, and they win, why I should I fall in with their unanimity? That can only be if we agree to be unanimous in backing the result. Like a democratic election? |
| 20608 | Unjust institutions may be seen as just; are they legitimate if just but seen as unjust? [Tuckness/Wolf] |
| Full Idea: Legitimacy and perceived legitimacy do not always go together: people can believe that their institutions are just, but they may be wrong. Is the reverse also possible? Can institutions be legitimate if people believe they are not? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'What are') | |
| A reaction: Nice thoughts. An institution cannot be just merely because it is seen that way (if someone gets away with rigging an election). If they are just but seen as unjust, I presume they are legitimate (which is objective), but disfunctional. |
| 20597 | If winning elections depends on wealth, we have plutocracy instead of democracy [Tuckness/Wolf] |
| Full Idea: If we let people's influence on election outcomes depend on their wealth, then we don't have a democracy any more. We have a plutocracy, where the people who have all the wealth have all the political power too. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Intro') | |
| A reaction: [see Michael Walzer on 'complex equality'] This is startling true in the United States, but still somewhat true elsewhere. Being wealthy enough to control the media is the key in modern democracies. |
| 20606 | Epistemic theories defend democracy as more likely to produce the right answer [Tuckness/Wolf] |
| Full Idea: According to epistemic theories of democracy, democratic outcomes are justified because they are more likely to be true or right than the choice of the individual. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Do the people') | |
| A reaction: Bear in mind Condorcet's proof that this claim is only correct if individuals have a better than 50% chance of being right, which may be so on obvious things, but is implausible for decisions like going to war. |
| 20600 | Which areas of public concern should be decided democratically, and which not? [Tuckness/Wolf] |
| Full Idea: Are there areas which are excluded from democratic decision making? Or should all issues of public concern be decided through a democratic process? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'What is') | |
| A reaction: Crucially, are we discussing direct democracy, or representative democracy? In Britain all major decisions are made by the cabinet. Our representatives appoint leaders, who then appoint the decision makers. Judiciary is non-democratic. |
| 20609 | If several losing groups would win if they combine, a runoff seems called for [Tuckness/Wolf] |
| Full Idea: It is possible that the people who supported several losing candidates might have joined forces and had a majority. For that reason, many countries have a runoff election. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Does democracy') | |
| A reaction: The problem is that there is no rationale as to who stands in an election. If their views are evenly spread, the first result seems OK. If there are five left-wingers and one right-winger, a runoff seems to be produce a more just result. |
| 20605 | Rights as interests (unlike rights as autonomy) supports mandatory voting [Tuckness/Wolf] |
| Full Idea: If rights concern people's interests, that might support mandatory voting, but if rights rely on protecting autonomy that might oppose it. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Interest') | |
| A reaction: I approach it from the other end, and am inclined to support mandatory voting, which suggests I am more concerned about interests than about autonomy. |
| 20599 | How should democratic votes be aggregated? Can some person's votes count for more? [Tuckness/Wolf] |
| Full Idea: A major question for democracy is how are the contributions of different people aggregated into a collective decision? Must votes have equal weight and consideration, or is it permissible for different people's votes to count differently? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'What is') | |
| A reaction: Mill hoped that wise and knowledgeable people would have a strong influence over the others, but we have recently moved into the post-truth era, where we are swamped by bogus facts. Does that strengthen the case for elite voting? |
| 20601 | Discussion before voting should be an essential part of democracy [Tuckness/Wolf] |
| Full Idea: According to advocates of deliberative democracy, people should have an opportunity to talk and reason with one another before votes are cast. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Who gets') | |
| A reaction: This is now done on Facebook and Twitter, but no one thinks that is sufficient. We will never again persuade most people to actually meet up and discuss issues. |
| 20613 | We have obligations to our family, even though we didn't choose its members [Tuckness/Wolf] |
| Full Idea: Many of our most important obligations are things we did not consent to. If you think you have obligations to your family, did you choose to have them as family members? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 6 'Gratitude') | |
| A reaction: A question that gets close to the heart of the communitarian ideal, I think. We choose to have children, and we bring them up, but even then we don't choose who our children are. |
| 20586 | Free speech does not include the right to shout 'Fire!' in a crowded theatre [Tuckness/Wolf] |
| Full Idea: Oliver Wendell Holmes (in 1919) noted that freedom of speech does not include the right to shout 'Fire!' in a crowded theatre. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 1 'Conflict') | |
| A reaction: The point here is that such irresponsible free speech does not even require legislation, and there is probably already some law under which the perpetrator could be prosecuted. |
| 20587 | Most people want equality because they want a flourishing life [Tuckness/Wolf] |
| Full Idea: If we want equality so much, we find that it is often because they think of equality as a prerequisite for a certain kind of flourishing life. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 1 'Happiness') | |
| A reaction: Most writers seem to agree that we don't want equality for its own sake. In what respects do we want to be equal? Why not equal in hair colour? Hence it looks as if equality drops out. I would aim to derive it from the social virtue of respect. |
| 20591 | If there is no suffering, wealth inequalities don't matter much [Tuckness/Wolf] |
| Full Idea: It is hard to get worked up over wealth inequalities if no one is suffering from them! | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 3 'Deprivation') | |
| A reaction: The more the poorer group resent the inequality, the more they suffer. When is resenting huge inequalities in wealth justified? It depends how the big wealth was obtained. |
| 20602 | Some rights are 'claims' that other people should act in a certain way [Tuckness/Wolf] |
| Full Idea: A 'claim right' is one in which the person asserting the right makes a claim on others to act or not act in a certain way. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Claim') | |
| A reaction: There seems to be a crucial distinction between rights which entail obligations on some individual or institution, and those which don't. Contracts (including employment contracts) generate duties on the parties. |
| 20604 | Choice theory says protecting individual autonomy is basic (but needs to cover infants and animals) [Tuckness/Wolf] |
| Full Idea: Choice theorists hold that rights protect our rights to make autonomous judgements, because our basic right to autonomy must be protected, The theory has a problem with people unable to exercise autonomy (such as infants and animals). | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Interest') | |
| A reaction: The problem of infants and animals looks like a decisive objection to me. We obviously don't protect dangerous or hostile autonomous judgements, and it is not clear why protecting stupid autonomy should be basic. |
| 20603 | One theory (fairly utilitarian) says rights protect interests (but it needs to cover trivial interests) [Tuckness/Wolf] |
| Full Idea: Interest theorists hold that rights serve to protect people's important interests. This is closely allied with utilitarian values. The theory has difficulty accounting for relatively trivial interests (like owning a lemonade you bought). | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Interest') | |
| A reaction: This sounds more plausible than choice theory (Idea 20604). It is obvious that infants must have rights. The lemonade problem seems to demand some sort of rule utilitarianism. Sidgwick looks promising. Rights can also be moral claims. |
| 20607 | Having a right does not entail further rights needed to implement it [Tuckness/Wolf] |
| Full Idea: Possession of a right (such as self-defence) does not always imply that one has additional rights to whatever they need (such as a handgun) in order to exercise the first right. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Is there') | |
| A reaction: The right to life entails a right to food (but not to a banquet), so it is a stronger right than self-defence. I have no obligation to let you defend yourself against me, but I may have an obligation to feed you if you are starving. (Distinction here?) |
| 20612 | If being subject to the law resembles a promise, we are morally obliged to obey it [Tuckness/Wolf] |
| Full Idea: One of the more common reasons people will give for having a moral obligation to obey the law is consent. ...It rests on the intuitively appealing idea of an analogy with a promise. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 6 'Consent') | |
| A reaction: [They cite Locke and Jefferson] In Locke's case it has to be a 'tacit' promise, which is more realistic. In real life we have problems with people who 'said' they would do something. They are often accused of promising, when they didn't. |
| 20611 | If others must obey laws that we like, we must obey laws that they like? [Tuckness/Wolf] |
| Full Idea: If we expect others to obey the laws we think just, do we have an obligation to obey the laws that other people think just? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 6 'What should') | |
| A reaction: Depends whether you have to be consistent about everything. I'm picky about which laws I obey, but I'm not going to tell you that, in case you get the same idea. Free riders. |
| 20610 | Instead of against natural law, we might assess unjust laws against the values of the culture [Tuckness/Wolf] |
| Full Idea: Do we need natural law theory in order to make sense of the idea that laws can be unjust? Perhaps not: we might consider whether laws are consistent with the values of the culture or society where they apply. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Unjust') | |
| A reaction: So were the wicked laws passed by the Nazis consistent with 1930s German culture? Impossible to say. |
| 20617 | How should the punishment fit the crime (for stealing chickens?) [Tuckness/Wolf] |
| Full Idea: One criticism of the retributive theory of punishment is that it is hard to know how to fit the punishment to the crime. What punishment should correspond to stealing chickens? | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 7 'Rationales') | |
| A reaction: The ancient world was more keen on restitution for such crimes, which makes much better sense. Buy them some chickens, plus twenty percent. |
| 20615 | Just wars: resist aggression, done on just cause, proportionate, last resort, not futile, legal [Tuckness/Wolf] |
| Full Idea: Classical just war theory: resist aggression; just cause must be the real reason; must be proportionate; last resort; not futile; made by a nation's authority. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 9 'Ius ad') | |
| A reaction: [My squashed summary of Tuckness and Wolf] A very helpful list, from Cicero, Augustine and Aquinas. So where is the sticking point for pacifists? Presumably it is never the last resort, and aggression should not answer aggression. |
| 20616 | During wars: proportional force, fair targets, fair weapons, safe prisoners, no reprisals [Tuckness/Wolf] |
| Full Idea: Classical just war theory during a war: force must be proportional; only legitimate targets; avoid prohibited weapons; safety for prisoners of war; no reprisals. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 9 'In the conduct') | |
| A reaction: What of massacre if a besieged city refuses to surrender? It was commonplace, and sometimes the only way to achieve victory. What if the enemy breaks all the rules? Nice rules though. At the heart of civilisation. |
| 20620 | If minority views are accepted in debate, then religious views must be accepted [Tuckness/Wolf] |
| Full Idea: It is unfair to exclude religious arguments from the public square because they are not accepted by everyone, unless other views that are not accepted by everyone are also excluded. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 9 'fairly') | |
| A reaction: Raises the obvious problems of a huge group in the grips of a fairly crazy view, and a tiny group (e.g. specialist scientists) in possession of a correct view. You can't just assess it on the size of the group. You can be wrong but reasonable. |
| 20619 | Is abortion the ending of a life, or a decision not to start one? [Tuckness/Wolf] |
| Full Idea: One group may consider abortion as a decision to end a life, while another may regard it as the decision not to start one. | |
| From: Tuckness,A/Wolf,C (This is Political Philosophy [2017], 8 'Hard I') | |
| A reaction: An early foetus is 'life', but is it 'a life'? Is a blade of grass 'a life'? Is a cell in a body 'a life'? |