72 ideas
15945 | Second-order set theory just adds a version of Replacement that quantifies over functions [Lavine] |
15914 | An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one [Lavine] |
15921 | Collections of things can't be too big, but collections by a rule seem unlimited in size [Lavine] |
15937 | Those who reject infinite collections also want to reject the Axiom of Choice [Lavine] |
15936 | The Power Set is just the collection of functions from one collection to another [Lavine] |
15899 | Replacement was immediately accepted, despite having very few implications [Lavine] |
15930 | Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets [Lavine] |
15920 | Pure collections of things obey Choice, but collections defined by a rule may not [Lavine] |
15898 | The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine] |
15919 | The 'logical' notion of class has some kind of definition or rule to characterise the class [Lavine] |
15900 | The iterative conception of set wasn't suggested until 1947 [Lavine] |
15931 | The iterative conception needs the Axiom of Infinity, to show how far we can iterate [Lavine] |
15932 | The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs [Lavine] |
15933 | Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement [Lavine] |
15913 | A collection is 'well-ordered' if there is a least element, and all of its successors can be identified [Lavine] |
15926 | Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine] |
15934 | Mathematical proof by contradiction needs the law of excluded middle [Lavine] |
15907 | Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine] |
15942 | Every rational number, unlike every natural number, is divisible by some other number [Lavine] |
15922 | For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine] |
18250 | Cauchy gave a necessary condition for the convergence of a sequence [Lavine] |
15904 | The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine] |
15912 | Counting results in well-ordering, and well-ordering makes counting possible [Lavine] |
15949 | The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine] |
15947 | The infinite is extrapolation from the experience of indefinitely large size [Lavine] |
15940 | The intuitionist endorses only the potential infinite [Lavine] |
15909 | 'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine] |
15915 | Ordinals are basic to Cantor's transfinite, to count the sets [Lavine] |
15917 | Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine] |
15918 | Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine] |
15929 | Set theory will found all of mathematics - except for the notion of proof [Lavine] |
15935 | Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine] |
15928 | Intuitionism rejects set-theory to found mathematics [Lavine] |
23101 | Intuitions don't prove things; they just receptivity to interpretations [Kekes] |
23086 | Liberals say we are only responsible for fully autonomous actions [Kekes] |
23100 | Collective responsibility conflicts with responsibility's requirement of authonomy [Kekes] |
20444 | If paintings could be perfectly duplicated, it would be a multiple art form [Currie, by Bacharach] |
23093 | Moral and causal responsibility are not clearly distinct [Kekes] |
23096 | Morality should aim to prevent all evil actions, not just autonomous ones [Kekes] |
23087 | Much human evil is not autonomous, so moral responsibility need not be autonomous [Kekes] |
23098 | Effects show the existence of moral responsibility, and mental states show the degree [Kekes] |
23089 | Evil people may not be autonomously aware, if they misjudge the situation [Kekes] |
23094 | Ought implies can means moral responsibility needs autonomy [Kekes] |
23095 | Why should moral responsibility depend on autonomy, rather than social role or experience? [Kekes] |
23090 | Liberals assume people are naturally free, equal, rational, and morally good [Kekes] |
23117 | Love should be partial, and discriminate in favour of its object [Kekes] |
23119 | Sentimental love distorts its object [Kekes] |
23088 | Evil is not deviation from the good, any more than good is a deviation from evil [Kekes] |
23097 | What matters for morality is the effects of action, not the psychological causes [Kekes] |
23099 | It is said that if an agent is not autonomous then their evil actions don't reflect on their character [Kekes] |
23118 | Awareness of others' suffering doesn't create an obligation to help [Kekes] |
23109 | The veil of ignorance is only needed because people have bad motivations [Kekes] |
23114 | The chief function of the state is to arbitrate between contending visions of the good life [Kekes] |
23116 | Citizenship is easier than parenthood [Kekes] |
23103 | Power is meant to be confined to representatives, and subsequent delegation [Kekes] |
23107 | Prosperity is a higher social virtue than justice [Kekes] |
23081 | Liberal basics are pluralism, freedom, rights, equality, and distributive justice - for autonomy [Kekes] |
23085 | The key liberal values are explained by the one core value, which is autonomy [Kekes] |
23092 | Agents have little control over the capacities needed for liberal autonomy [Kekes] |
23102 | Liberals are egalitarians, but in varying degrees [Kekes] |
23084 | Are egalitarians too coercive, or not egalitarian enough, or lax over morality? [Kekes] |
23079 | Liberal justice ignores desert, which is the essence of justice [Kekes] |
23091 | Why do liberals not see a much wider range of values as basic? [Kekes] |
23112 | Liberals ignore contingency, and think people are good and equal, and institutions cause evil [Kekes] |
23082 | Liberal distribution cares more about recipients than donors [Kekes] |
23106 | To rectify the undeserved equality, we should give men longer and women shorter lives [Kekes] |
23121 | It is just a fact that some people are morally better than others [Kekes] |
23105 | It is not deplorable that billionaires have more than millionaires [Kekes] |
23120 | The problem is basic insufficiency of resources, not their inequality [Kekes] |
23108 | Justice combines consistency and desert; treat likes alike, judging likeness by desert [Kekes] |
23083 | Liberal welfare focuses on need rather than desert [Kekes] |
23113 | Sexual morality doesn't require monogamy, but it needs a group of sensible regulations [Kekes] |