47 ideas
9218 | Maybe what distinguishes philosophy from science is its pursuit of necessary truths [Sider] |
10859 | A set is 'well-ordered' if every subset has a first element [Clegg] |
10857 | Set theory made a closer study of infinity possible [Clegg] |
10864 | Any set can always generate a larger set - its powerset, of subsets [Clegg] |
10872 | Extensionality: Two sets are equal if and only if they have the same elements [Clegg] |
10875 | Pairing: For any two sets there exists a set to which they both belong [Clegg] |
10876 | Unions: There is a set of all the elements which belong to at least one set in a collection [Clegg] |
10878 | Infinity: There exists a set of the empty set and the successor of each element [Clegg] |
10877 | Powers: All the subsets of a given set form their own new powerset [Clegg] |
10879 | Choice: For every set a mechanism will choose one member of any non-empty subset [Clegg] |
10871 | Axiom of Existence: there exists at least one set [Clegg] |
10874 | Specification: a condition applied to a set will always produce a new set [Clegg] |
10880 | Mathematics can be 'pure' (unapplied), 'real' (physically grounded); or 'applied' (just applicable) [Clegg] |
10861 | Beyond infinity cardinals and ordinals can come apart [Clegg] |
10860 | An ordinal number is defined by the set that comes before it [Clegg] |
10854 | Transcendental numbers can't be fitted to finite equations [Clegg] |
10858 | By adding an axis of imaginary numbers, we get the useful 'number plane' instead of number line [Clegg] |
10853 | Either lack of zero made early mathematics geometrical, or the geometrical approach made zero meaningless [Clegg] |
10866 | Cantor's account of infinities has the shaky foundation of irrational numbers [Clegg] |
10869 | The Continuum Hypothesis is independent of the axioms of set theory [Clegg] |
10862 | The 'continuum hypothesis' says aleph-one is the cardinality of the reals [Clegg] |
2730 | Because 'gold is malleable' is necessary does not mean that it is analytic [Audi,R] |
2715 | Beliefs are based on perception, memory, introspection or reason [Audi,R] |
2735 | Could you have a single belief on its own? [Audi,R] |
2736 | We can make certain of what we know, so knowing does not entail certainty [Audi,R] |
2722 | Sense-data theory is indirect realism, but phenomenalism is direct irrealism [Audi,R] |
2721 | If you gradually remove a book's sensory properties, what is left at the end? [Audi,R] |
2727 | Red and green being exclusive colours seems to be rationally graspable but not analytic [Audi,R] |
2728 | The concepts needed for a priori thought may come from experience [Audi,R] |
2716 | To see something as a field, I obviously need the concept of a field [Audi,R] |
2717 | How could I see a field and believe nothing regarding it? [Audi,R] |
2720 | Sense-data (and the rival 'adverbial' theory) are to explain illusions and hallucinations [Audi,R] |
2719 | Sense data imply representative realism, possibly only representing primary qualities [Audi,R] |
2718 | Perception is first simple, then objectual (with concepts) and then propositional [Audi,R] |
2741 | The principles of justification have to be a priori [Audi,R] |
2729 | Virtually all rationalists assert that we can have knowledge of synthetic a priori truths [Audi,R] |
2725 | To remember something is to know it [Audi,R] |
2724 | I might remember someone I can't recall or image, by recognising them on meeting [Audi,R] |
2731 | Justification is either unanchored (infinite or circular), or anchored (in knowledge or non-knowledge) [Audi,R] |
2739 | Internalism about justification implies that there is a right to believe something [Audi,R] |
2732 | Maths may be consistent with observations, but not coherent [Audi,R] |
2733 | It is very hard to show how much coherence is needed for justification [Audi,R] |
2734 | A consistent madman could have a very coherent belief system [Audi,R] |
2738 | Consistent accurate prediction looks like knowledge without justified belief [Audi,R] |
2740 | A reliability theory of knowledge seems to involve truth as correspondence [Audi,R] |
2737 | 'Reliable' is a very imprecise term, and may even mean 'justified' [Audi,R] |
2726 | We can be ignorant about ourselves, for example, our desires and motives [Audi,R] |