42 ideas
7786 | Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle] |
7798 | There are three axiom schemas for propositional logic [Girle] |
7799 | Proposition logic has definitions for its three operators: or, and, and identical [Girle] |
7797 | Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle] |
7794 | There are seven modalities in S4, each with its negation [Girle] |
7793 | ◊p → □◊p is the hallmark of S5 [Girle] |
7795 | S5 has just six modalities, and all strings can be reduced to those [Girle] |
7787 | Possible worlds logics use true-in-a-world rather than true [Girle] |
7788 | Modal logic has four basic modal negation equivalences [Girle] |
7796 | Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle] |
7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
2730 | Because 'gold is malleable' is necessary does not mean that it is analytic [Audi,R] |
7801 | Possibilities can be logical, theoretical, physical, economic or human [Girle] |
7792 | A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle] |
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] |
2721 | If you gradually remove a book's sensory properties, what is left at the end? [Audi,R] |
2722 | Sense-data theory is indirect realism, but phenomenalism is direct irrealism [Audi,R] |
2728 | The concepts needed for a priori thought may come from experience [Audi,R] |
2727 | Red and green being exclusive colours seems to be rationally graspable but not analytic [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] |
2719 | Sense data imply representative realism, possibly only representing primary qualities [Audi,R] |
2720 | Sense-data (and the rival 'adverbial' theory) are to explain illusions and hallucinations [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] |
6649 | Chomsky now says concepts are basically innate, as well as syntax [Chomsky, by Lowe] |