52 ideas
| 16877 | A 'constructive' (as opposed to 'analytic') definition creates a new sign [Frege] |
| Full Idea: We construct a sense out of its constituents and introduce an entirely new sign to express this sense. This may be called a 'constructive definition', but we prefer to call it a 'definition' tout court. It contrasts with an 'analytic' definition. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.210) | |
| A reaction: An analytic definition is evidently a deconstruction of a past constructive definition. Fregean definition is a creative activity. |
| 11219 | Frege suggested that mathematics should only accept stipulative definitions [Frege, by Gupta] |
| Full Idea: Frege has defended the austere view that, in mathematics at least, only stipulative definitions should be countenanced. | |
| From: report of Gottlob Frege (Logic in Mathematics [1914]) by Anil Gupta - Definitions 1.3 | |
| A reaction: This sounds intriguingly at odds with Frege's well-known platonism about numbers (as sets of equinumerous sets). It makes sense for other mathematical concepts. |
| 16878 | We must be clear about every premise and every law used in a proof [Frege] |
| Full Idea: It is so important, if we are to have a clear insight into what is going on, for us to be able to recognise the premises of every inference which occurs in a proof and the law of inference in accordance with which it takes place. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.212) | |
| A reaction: Teachers of logic like natural deduction, because it reduces everything to a few clear laws, which can be stated at each step. |
| 16867 | Logic not only proves things, but also reveals logical relations between them [Frege] |
| Full Idea: A proof does not only serve to convince us of the truth of what is proved: it also serves to reveal logical relations between truths. Hence we find in Euclid proofs of truths that appear to stand in no need of proof because they are obvious without one. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.204) | |
| A reaction: This is a key idea in Frege's philosophy, and a reason why he is the founder of modern analytic philosophy, with logic placed at the centre of the subject. I take the value of proofs to be raising questions, more than giving answers. |
| 16863 | Does some mathematical reasoning (such as mathematical induction) not belong to logic? [Frege] |
| Full Idea: Are there perhaps modes of inference peculiar to mathematics which …do not belong to logic? Here one may point to inference by mathematical induction from n to n+1. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.203) | |
| A reaction: He replies that it looks as if induction can be reduced to general laws, and those can be reduced to logic. |
| 16862 | The closest subject to logic is mathematics, which does little apart from drawing inferences [Frege] |
| Full Idea: Mathematics has closer ties with logic than does almost any other discipline; for almost the entire activity of the mathematician consists in drawing inferences. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.203) | |
| A reaction: The interesting question is who is in charge - the mathematician or the logician? |
| 16865 | 'Theorems' are both proved, and used in proofs [Frege] |
| Full Idea: Usually a truth is only called a 'theorem' when it has not merely been obtained by inference, but is used in turn as a premise for a number of inferences in the science. ….Proofs use non-theorems, which only occur in that proof. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.204) |
| 16866 | Tracing inference backwards closes in on a small set of axioms and postulates [Frege] |
| Full Idea: We can trace the chains of inference backwards, …and the circle of theorems closes in more and more. ..We must eventually come to an end by arriving at truths can cannot be inferred, …which are the axioms and postulates. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.204) | |
| A reaction: The rival (more modern) view is that that all theorems are equal in status, and axioms are selected for convenience. |
| 16868 | The essence of mathematics is the kernel of primitive truths on which it rests [Frege] |
| Full Idea: Science must endeavour to make the circle of unprovable primitive truths as small as possible, for the whole of mathematics is contained in this kernel. The essence of mathematics has to be defined by this kernel of truths. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.204-5) | |
| A reaction: [compressed] I will make use of this thought, by arguing that mathematics may be 'explained' by this kernel. |
| 16870 | Axioms are truths which cannot be doubted, and for which no proof is needed [Frege] |
| Full Idea: The axioms are theorems, but truths for which no proof can be given in our system, and no proof is needed. It follows from this that there are no false axioms, and we cannot accept a thought as an axiom if we are in doubt about its truth. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.205) | |
| A reaction: He struggles to be as objective as possible, but has to concede that whether we can 'doubt' the axiom is one of the criteria. |
| 16871 | A truth can be an axiom in one system and not in another [Frege] |
| Full Idea: It is possible for a truth to be an axiom in one system and not in another. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.205) | |
| A reaction: Frege aspired to one huge single system, so this is a begrudging concession, one which modern thinkers would probably take for granted. |
| 16869 | To create order in mathematics we need a full system, guided by patterns of inference [Frege] |
| Full Idea: We cannot long remain content with the present fragmentation [of mathematics]. Order can be created only by a system. But to construct a system it is necessary that in any step forward we take we should be aware of the logical inferences involved. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.205) |
| 16864 | If principles are provable, they are theorems; if not, they are axioms [Frege] |
| Full Idea: If the law [of induction] can be proved, it will be included amongst the theorems of mathematics; if it cannot, it will be included amongst the axioms. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.203) | |
| A reaction: This links Frege with the traditional Euclidean view of axioms. The question, then, is how do we know them, given that we can't prove them. |
| 9388 | Every concept must have a sharp boundary; we cannot allow an indeterminate third case [Frege] |
| Full Idea: Of any concept, we must require that it have a sharp boundary. Of any object it must hold either that it falls under the concept or it does not. We may not allow a third case in which it is somehow indeterminate whether an object falls under a concept. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.229), quoted by Ian Rumfitt - The Logic of Boundaryless Concepts p.1 n1 | |
| A reaction: This is the voice of the classical logician, which has echoed by Russell. I'm with them, I think, in the sense that logic can only work with precise concepts. The jury is still out. Maybe we can 'precisify', without achieving total precision. |
| 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? |
| 16876 | We need definitions to cram retrievable sense into a signed receptacle [Frege] |
| Full Idea: If we need such signs, we also need definitions so that we can cram this sense into the receptacle and also take it out again. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.209) | |
| A reaction: Has anyone noticed that Frege is the originator of the idea of the mental file? Has anyone noticed the role that definition plays in his account? |
| 16875 | We use signs to mark receptacles for complex senses [Frege] |
| Full Idea: We often need to use a sign with which we associate a very complex sense. Such a sign seems a receptacle for the sense, so that we can carry it with us, while being always aware that we can open this receptacle should we need what it contains. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.209) | |
| A reaction: This exactly the concept of a mental file, which I enthusiastically endorse. Frege even talks of 'opening the receptacle'. For Frege a definition (which he has been discussing) is the assigment of a label (the 'definiendum') to the file (the 'definiens'). |
| 16879 | A sign won't gain sense just from being used in sentences with familiar components [Frege] |
| Full Idea: No sense accrues to a sign by the mere fact that it is used in one or more sentences, the other constituents of which are known. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.213) | |
| A reaction: Music to my ears. I've never grasped how meaning could be grasped entirely through use. |
| 16873 | Thoughts are not subjective or psychological, because some thoughts are the same for us all [Frege] |
| Full Idea: A thought is not something subjective, is not the product of any form of mental activity; for the thought that we have in Pythagoras's theorem is the same for everybody. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.206) | |
| A reaction: When such thoughts are treated as if the have objective (platonic) existence, I become bewildered. I take a thought (or proposition) to be entirely psychological, but that doesn't stop two people from having the same thought. |
| 16872 | A thought is the sense expressed by a sentence, and is what we prove [Frege] |
| Full Idea: The sentence is of value to us because of the sense that we grasp in it, which is recognisably the same in a translation. I call this sense the thought. What we prove is not a sentence, but a thought. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.206) | |
| A reaction: The 'sense' is presumably the German 'sinn', and a 'thought' in Frege is what we normally call a 'proposition'. So the sense of a sentence is a proposition, and logic proves propositions. I'm happy with that. |
| 16874 | The parts of a thought map onto the parts of a sentence [Frege] |
| Full Idea: A sentence is generally a complex sign, so the thought expressed by it is complex too: in fact it is put together in such a way that parts of a thought correspond to parts of the sentence. | |
| From: Gottlob Frege (Logic in Mathematics [1914], p.207) | |
| A reaction: This is the compositional view of propositions, as opposed to the holistic view. |
| 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'? |
| 12709 | Motion is not absolute, but consists in relation [Leibniz] |
| Full Idea: In reality motion is not something absolute, but consists in relation. | |
| From: Gottfried Leibniz (On Motion [1677], A6.4.1968), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 3 | |
| A reaction: It is often thought that motion being relative was invented by Einstein, but Leibniz wholeheartedly embraced 'Galilean relativity', and refused to even consider any absolute concept of motion. Acceleration is a bit trickier than velocity. |