28 ideas
18274 | Analysis complicates a statement, but only as far as the complexity of its meaning [Wittgenstein] |
10528 | Definitions concern how we should speak, not how things are [Fine,K] |
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] |
16908 | We can dispense with self-evidence, if language itself prevents logical mistakes [Jeshion on Wittgenstein] |
7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
18276 | A statement's logical form derives entirely from its constituents [Wittgenstein] |
6563 | 'And' and 'not' are non-referring terms, which do not represent anything [Wittgenstein, by Fogelin] |
7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
10529 | If Hume's Principle can define numbers, we needn't worry about its truth [Fine,K] |
10530 | Hume's Principle is either adequate for number but fails to define properly, or vice versa [Fine,K] |
23472 | The sense of propositions relies on the world's basic logical structure [Wittgenstein] |
7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
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] |
23500 | My main problem is the order of the world, and whether it is knowable a priori [Wittgenstein] |
22323 | The philosophical I is the metaphysical subject, the limit - not a part of the world [Wittgenstein] |
10527 | An abstraction principle should not 'inflate', producing more abstractions than objects [Fine,K] |
23481 | Propositions assemble a world experimentally, like the model of a road accident [Wittgenstein] |
4678 | Absolute prohibitions are the essence of ethics, and suicide is the most obvious example [Wittgenstein] |