86 ideas
10482 | The logic of ZF is classical first-order predicate logic with identity [Boolos] |
10492 | A few axioms of set theory 'force themselves on us', but most of them don't [Boolos] |
18192 | Do the Replacement Axioms exceed the iterative conception of sets? [Boolos, by Maddy] |
7785 | The use of plurals doesn't commit us to sets; there do not exist individuals and collections [Boolos] |
10485 | Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos] |
10484 | The iterative conception says sets are formed at stages; some are 'earlier', and must be formed first [Boolos] |
13547 | Limitation of Size is weak (Fs only collect is something the same size does) or strong (fewer Fs than objects) [Boolos, by Potter] |
10699 | Does a bowl of Cheerios contain all its sets and subsets? [Boolos] |
14249 | Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley] |
10830 | Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos] |
10225 | Monadic second-order logic might be understood in terms of plural quantifiers [Boolos, by Shapiro] |
10736 | Boolos showed how plural quantifiers can interpret monadic second-order logic [Boolos, by Linnebo] |
10780 | Any sentence of monadic second-order logic can be translated into plural first-order logic [Boolos, by Linnebo] |
10829 | A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos] |
10697 | Identity is clearly a logical concept, and greatly enhances predicate calculus [Boolos] |
10832 | '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos] |
13671 | Second-order quantifiers are just like plural quantifiers in ordinary language, with no extra ontology [Boolos, by Shapiro] |
10267 | We should understand second-order existential quantifiers as plural quantifiers [Boolos, by Shapiro] |
10698 | Plural forms have no more ontological commitment than to first-order objects [Boolos] |
7806 | Boolos invented plural quantification [Boolos, by Benardete,JA] |
10834 | Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos] |
13841 | Why should compactness be definitive of logic? [Boolos, by Hacking] |
10491 | Infinite natural numbers is as obvious as infinite sentences in English [Boolos] |
10483 | Mathematics and science do not require very high orders of infinity [Boolos] |
10833 | Many concepts can only be expressed by second-order logic [Boolos] |
10490 | Mathematics isn't surprising, given that we experience many objects as abstract [Boolos] |
10700 | First- and second-order quantifiers are two ways of referring to the same things [Boolos] |
16661 | There are two sorts of category - referring to things, and to circumstances of things [Boethius] |
10488 | It is lunacy to think we only see ink-marks, and not word-types [Boolos] |
15035 | If universals are not separate, we can isolate them by abstraction [Boethius, by Panaccio] |
10487 | I am a fan of abstract objects, and confident of their existence [Boolos] |
10489 | We deal with abstract objects all the time: software, poems, mistakes, triangles.. [Boolos] |
14665 | We can call the quality of Plato 'Platonity', and say it is a quality which only he possesses [Boethius] |
23308 | Reasoning relates to understanding as time does to eternity [Boethius, by Sorabji] |
4363 | The word 'person' is useless in ethics, because what counts as a good or bad self-conscious being? [Hursthouse] |
5771 | Knowledge of present events doesn't make them necessary, so future events are no different [Boethius] |
5767 | Rational natures require free will, in order to have power of judgement [Boethius] |
5768 | God's universal foreknowledge seems opposed to free will [Boethius] |
5769 | Does foreknowledge cause necessity, or necessity cause foreknowledge? [Boethius] |
8693 | An 'abstraction principle' says two things are identical if they are 'equivalent' in some respect [Boolos] |
4355 | There may be inverse akrasia, where the agent's action is better than their judgement recommends [Hursthouse] |
4325 | Must all actions be caused in part by a desire, or can a belief on its own be sufficient? [Hursthouse] |
5762 | The wicked want goodness, so they would not be wicked if they obtained it [Boethius] |
4351 | It is a fantasy that only through the study of philosophy can one become virtuous [Hursthouse] |
4329 | After a moral dilemma is resolved there is still a 'remainder', requiring (say) regret [Hursthouse] |
4330 | Deontologists resolve moral dilemmas by saying the rule conflict is merely apparent [Hursthouse] |
4341 | Involuntary actions performed in tragic dilemmas are bad because they mar a good life [Hursthouse] |
4340 | You are not a dishonest person if a tragic dilemma forces you to do something dishonest [Hursthouse] |
5770 | Rewards and punishments are not deserved if they don't arise from free movement of the mind [Boethius] |
5764 | When people fall into wickedness they lose their human nature [Boethius] |
4358 | Virtue may be neither sufficient nor necessary for eudaimonia [Hursthouse] |
4337 | Teenagers are often quite wise about ideals, but rather stupid about consequences [Hursthouse] |
5756 | Happiness is a good which once obtained leaves nothing more to be desired [Boethius] |
4324 | Animals and plants can 'flourish', but only rational beings can have eudaimonia [Hursthouse] |
5763 | The bad seek the good through desire, but the good through virtue, which is more natural [Boethius] |
4359 | When it comes to bringing up children, most of us think that the virtues are the best bet [Hursthouse] |
20195 | Eudaimonia first; virtue is a trait which promotes it; right acts are what virtues produce [Hursthouse, by Zagzebski] |
4336 | Any strict ranking of virtues or rules gets abandoned when faced with particular cases [Hursthouse] |
4334 | Virtue ethics is open to the objection that it fails to show priority among the virtues [Hursthouse] |
4361 | Good animals can survive, breed, feel characteristic pleasure and pain, and contribute to the group [Hursthouse] |
4349 | Virtuous people may not be fully clear about their reasons for action [Hursthouse] |
4352 | Performing an act simply because it is virtuous is sufficient to be 'morally motivated' or 'dutiful' [Hursthouse] |
4353 | If moral motivation is an all-or-nothing sense of duty, how can children act morally? [Hursthouse] |
4346 | The emotions of sympathy, compassion and love are no guarantee of right action or acting well [Hursthouse] |
4339 | According to virtue ethics, two agents may respond differently, and yet both be right [Hursthouse] |
5759 | Varied aims cannot be good because they differ, but only become good when they unify [Boethius] |
4354 | Maybe in a deeply poisoned character none of their milder character traits could ever be a virtue [Hursthouse] |
4356 | We are puzzled by a person who can show an exceptional virtue and also behave very badly [Hursthouse] |
4364 | Being unusually virtuous in some areas may entail being less virtuous in others [Hursthouse] |
4327 | Deontologists do consider consequences, because they reveal when a rule might apply [Hursthouse] |
4335 | 'Codifiable' morality give rules for decisions which don't require wisdom [Hursthouse] |
4328 | Preference utilitarianism aims to be completely value-free, or empirical [Hursthouse] |
4338 | Deontologists usually accuse utilitarians of oversimplifying hard cases [Hursthouse] |
4343 | We are torn between utilitarian and deontological views of lying, depending on the examples [Hursthouse] |
4365 | We are distinct from other animals in behaving rationally - pursuing something as good, for reasons [Hursthouse] |
5754 | You can't control someone's free mind, only their body and possessions [Boethius] |
16692 | Divine eternity is the all-at-once and complete possession of unending life [Boethius] |
5752 | Where does evil come from if there is a god; where does good come from if there isn't? [Boethius] |
4350 | If people are virtuous in obedience to God, would they become wicked if they lost their faith? [Hursthouse] |
5757 | God is the supreme good, so no source of goodness could take precedence over God [Boethius] |
5758 | God is the good [Boethius] |
5760 | The power through which creation remains in existence and motion I call 'God' [Boethius] |
5753 | The regular events of this life could never be due to chance [Boethius] |
5765 | The reward of the good is to become gods [Boethius] |
5761 | God can do anything, but he cannot do evil, so evil must be nothing [Boethius] |
5766 | If you could see the plan of Providence, you would not think there was evil anywhere [Boethius] |