53 ideas
17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
17765 | Propositional language can only relate statements as the same or as different [Walicki] |
17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
17754 | Inductive proof depends on the choice of the ordering [Walicki] |
17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
20589 | Maybe a person's true self is their second-order desires [Tuckness/Wolf] |
20327 | Modern attention has moved from the intrinsic properties of art to its relational properties [Lamarque/Olson] |
20326 | Early 20th cent attempts at defining art focused on significant form, intuition, expression, unity [Lamarque/Olson] |
20330 | The dualistic view says works of art are either abstract objects (types), or physical objects [Lamarque/Olson] |
20583 | If maximising pleasure needs measurement, so does fulfilling desires [Tuckness/Wolf] |
20584 | Desire satisfaction as the ideal is confused, because we desire what we judge to be good [Tuckness/Wolf] |
20598 | In a democracy, which 'people' are included in the decision process? [Tuckness/Wolf] |
20614 | People often have greater attachment to ethnic or tribal groups than to the state [Tuckness/Wolf] |
20596 | For global justice, adopt rules without knowing which country you will inhabit [Tuckness/Wolf] |
20593 | The veil of ignorance ensures both fairness and unanimity [Tuckness/Wolf] |
20608 | Unjust institutions may be seen as just; are they legitimate if just but seen as unjust? [Tuckness/Wolf] |
20597 | If winning elections depends on wealth, we have plutocracy instead of democracy [Tuckness/Wolf] |
20606 | Epistemic theories defend democracy as more likely to produce the right answer [Tuckness/Wolf] |
20600 | Which areas of public concern should be decided democratically, and which not? [Tuckness/Wolf] |
20609 | If several losing groups would win if they combine, a runoff seems called for [Tuckness/Wolf] |
20605 | Rights as interests (unlike rights as autonomy) supports mandatory voting [Tuckness/Wolf] |
20599 | How should democratic votes be aggregated? Can some person's votes count for more? [Tuckness/Wolf] |
20601 | Discussion before voting should be an essential part of democracy [Tuckness/Wolf] |
20613 | We have obligations to our family, even though we didn't choose its members [Tuckness/Wolf] |
20586 | Free speech does not include the right to shout 'Fire!' in a crowded theatre [Tuckness/Wolf] |
20587 | Most people want equality because they want a flourishing life [Tuckness/Wolf] |
20591 | If there is no suffering, wealth inequalities don't matter much [Tuckness/Wolf] |
20602 | Some rights are 'claims' that other people should act in a certain way [Tuckness/Wolf] |
20604 | Choice theory says protecting individual autonomy is basic (but needs to cover infants and animals) [Tuckness/Wolf] |
20603 | One theory (fairly utilitarian) says rights protect interests (but it needs to cover trivial interests) [Tuckness/Wolf] |
20607 | Having a right does not entail further rights needed to implement it [Tuckness/Wolf] |
20612 | If being subject to the law resembles a promise, we are morally obliged to obey it [Tuckness/Wolf] |
20611 | If others must obey laws that we like, we must obey laws that they like? [Tuckness/Wolf] |
20610 | Instead of against natural law, we might assess unjust laws against the values of the culture [Tuckness/Wolf] |
20617 | How should the punishment fit the crime (for stealing chickens?) [Tuckness/Wolf] |
20615 | Just wars: resist aggression, done on just cause, proportionate, last resort, not futile, legal [Tuckness/Wolf] |
20616 | During wars: proportional force, fair targets, fair weapons, safe prisoners, no reprisals [Tuckness/Wolf] |
20620 | If minority views are accepted in debate, then religious views must be accepted [Tuckness/Wolf] |
20619 | Is abortion the ending of a life, or a decision not to start one? [Tuckness/Wolf] |