50 ideas
17774 | Definitions make our intuitions mathematically useful [Mayberry] |
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] |
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] |
17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
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] |
15201 | That Queen Anne is dead is a 'general fact', not a fact about Queen Anne [Prior,AN] |
15435 | If you think universals are immanent, you must believe them to be sparse, and not every related predicate [Lewis] |
15451 | I assume there could be natural properties that are not instantiated in our world [Lewis] |
15433 | Tropes are particular properties, which cannot recur, but can be exact duplicates [Lewis] |
15436 | Universals are meant to give an account of resemblance [Lewis] |
15438 | We can add a primitive natural/unnatural distinction to class nominalism [Lewis] |
17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
15448 | The 'magical' view of structural universals says they are atoms, even though they have parts [Lewis] |
15449 | If 'methane' is an atomic structural universal, it has nothing to connect it to its carbon universals [Lewis] |
15439 | The 'pictorial' view of structural universals says they are wholes made of universals as parts [Lewis] |
15441 | The structural universal 'methane' needs the universal 'hydrogen' four times over [Lewis] |
15445 | Butane and Isobutane have the same atoms, but different structures [Lewis] |
15434 | Structural universals have a necessary connection to the universals forming its parts [Lewis] |
15437 | We can't get rid of structural universals if there are no simple universals [Lewis] |
15446 | Composition is not just making new things from old; there are too many counterexamples [Lewis] |
15440 | A whole is distinct from its parts, but is not a further addition in ontology [Lewis] |
15444 | Different things (a toy house and toy car) can be made of the same parts at different times [Lewis] |
15450 | Maybe abstraction is just mereological subtraction [Lewis] |
15443 | Mathematicians abstract by equivalence classes, but that doesn't turn a many into one [Lewis] |
22899 | 'Thank goodness that's over' is not like 'thank goodness that happened on Friday' [Prior,AN] |