69 ideas
8060 | In the 17th-18th centuries morality offered a cure for egoism, through altruism [MacIntyre] |
8053 | Twentieth century social life is re-enacting eighteenth century philosophy [MacIntyre] |
8047 | Philosophy has been marginalised by its failure in the Enlightenment to replace religion [MacIntyre] |
8062 | Proof is a barren idea in philosophy, and the best philosophy never involves proof [MacIntyre] |
17774 | Definitions make our intuitions mathematically useful [Mayberry] |
21704 | 'Impredictative' definitions fix a class in terms of the greater class to which it belongs [Linsky,B] |
17773 | Proof shows that it is true, but also why it must be true [Mayberry] |
17795 | Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry] |
17796 | There is a semi-categorical axiomatisation of set-theory [Mayberry] |
17800 | The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry] |
21705 | Reducibility says any impredicative function has an appropriate predicative replacement [Linsky,B] |
17801 | The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry] |
17803 | Limitation of size is part of the very conception of a set [Mayberry] |
17786 | The mainstream of modern logic sees it as a branch of mathematics [Mayberry] |
17788 | First-order logic only has its main theorems because it is so weak [Mayberry] |
17791 | Only second-order logic can capture mathematical structure up to isomorphism [Mayberry] |
21727 | Definite descriptions theory eliminates the King of France, but not the Queen of England [Linsky,B] |
17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
21719 | Extensionalism means what is true of a function is true of coextensive functions [Linsky,B] |
17790 | No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry] |
17779 | 'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry] |
17778 | Axiomatiation relies on isomorphic structures being essentially the same [Mayberry] |
17780 | 'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry] |
17789 | No logic which can axiomatise arithmetic can be compact or complete [Mayberry] |
17784 | Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry] |
17782 | Greek quantities were concrete, and ratio and proportion were their science [Mayberry] |
17781 | Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry] |
17799 | Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry] |
17797 | Cantor extended the finite (rather than 'taming the infinite') [Mayberry] |
17775 | If proof and definition are central, then mathematics needs and possesses foundations [Mayberry] |
17776 | The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry] |
17777 | Foundations need concepts, definition rules, premises, and proof rules [Mayberry] |
17804 | Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry] |
17792 | 1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry] |
17793 | It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry] |
17794 | Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry] |
17802 | We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry] |
17805 | Set theory is not just another axiomatised part of mathematics [Mayberry] |
21723 | The task of logicism was to define by logic the concepts 'number', 'successor' and '0' [Linsky,B] |
21721 | Higher types are needed to distinguished intensional phenomena which are coextensive [Linsky,B] |
21703 | Types are 'ramified' when there are further differences between the type of quantifier and its range [Linsky,B] |
21714 | The ramified theory subdivides each type, according to the range of the variables [Linsky,B] |
21713 | Did logicism fail, when Russell added three nonlogical axioms, to save mathematics? [Linsky,B] |
21715 | For those who abandon logicism, standard set theory is a rival option [Linsky,B] |
21729 | Construct properties as sets of objects, or say an object must be in the set to have the property [Linsky,B] |
17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
8052 | To find empiricism and science in the same culture is surprising, as they are really incompatible [MacIntyre] |
8057 | Unpredictability doesn't entail inexplicability, and predictability doesn't entail explicability [MacIntyre] |
8054 | Social sciences discover no law-like generalisations, and tend to ignore counterexamples [MacIntyre] |
21050 | I can only make decisions if I see myself as part of a story [MacIntyre] |
8056 | AI can't predict innovation, or consequences, or external relations, or external events [MacIntyre] |
8059 | The good life for man is the life spent seeking the good life for man [MacIntyre] |
8034 | We still have the appearance and language of morality, but we no longer understand it [MacIntyre] |
8036 | Unlike expressions of personal preference, evaluative expressions do not depend on context [MacIntyre] |
8049 | Moral judgements now are anachronisms from a theistic age [MacIntyre] |
8045 | The failure of Enlightenment attempts to justify morality will explain our own culture [MacIntyre] |
8051 | Mention of 'intuition' in morality means something has gone wrong with the argument [MacIntyre] |
8048 | When 'man' is thought of individually, apart from all roles, it ceases to be a functional concept [MacIntyre] |
8035 | In trying to explain the type of approval involved, emotivists are either silent, or viciously circular [MacIntyre] |
8037 | The expression of feeling in a sentence is in its use, not in its meaning [MacIntyre] |
8040 | Emotivism cannot explain the logical terms in moral discourse ('therefore', 'if..then') [MacIntyre] |
8042 | Nowadays most people are emotivists, and it is embodied in our culture [MacIntyre] |
8058 | Maybe we can only understand rules if we first understand the virtues [MacIntyre] |
7097 | Virtue is secondary to a role-figure, defined within a culture [MacIntyre, by Statman] |
8043 | Characters are the masks worn by moral philosophies [MacIntyre] |
8061 | If morality just is emotion, there are no external criteria for judging emotions [MacIntyre] |
8038 | Since Moore thinks the right action produces the most good, he is a utilitarian [MacIntyre] |
8050 | There are no natural or human rights, and belief in them is nonsense [MacIntyre] |
8055 | If God is omniscient, he confronts no as yet unmade decisions, so decisions are impossible [MacIntyre] |