62 ideas
8166 | Truth is part of semantics, since valid inference preserves truth [Dummett] |
10170 | While true-in-a-model seems relative, true-in-all-models seems not to be [Reck/Price] |
10166 | ZFC set theory has only 'pure' sets, without 'urelements' [Reck/Price] |
8173 | Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett] |
8179 | The law of excluded middle is the logical reflection of the principle of bivalence [Dummett] |
10175 | Three types of variable in second-order logic, for objects, functions, and predicates/sets [Reck/Price] |
10165 | 'Analysis' is the theory of the real numbers [Reck/Price] |
10174 | Mereological arithmetic needs infinite objects, and function definitions [Reck/Price] |
10164 | Peano Arithmetic can have three second-order axioms, plus '1' and 'successor' [Reck/Price] |
10172 | Set-theory gives a unified and an explicit basis for mathematics [Reck/Price] |
10167 | Structuralism emerged from abstract algebra, axioms, and set theory and its structures [Reck/Price] |
10169 | Relativist Structuralism just stipulates one successful model as its arithmetic [Reck/Price] |
10179 | There are 'particular' structures, and 'universal' structures (what the former have in common) [Reck/Price] |
10181 | Pattern Structuralism studies what isomorphic arithmetic models have in common [Reck/Price] |
10182 | There are Formalist, Relativist, Universalist and Pattern structuralism [Reck/Price] |
10168 | Formalist Structuralism says the ontology is vacuous, or formal, or inference relations [Reck/Price] |
10178 | Maybe we should talk of an infinity of 'possible' objects, to avoid arithmetic being vacuous [Reck/Price] |
10176 | Universalist Structuralism is based on generalised if-then claims, not one particular model [Reck/Price] |
10177 | Universalist Structuralism eliminates the base element, as a variable, which is then quantified out [Reck/Price] |
10171 | The existence of an infinite set is assumed by Relativist Structuralism [Reck/Price] |
8184 | Philosophers should not presume reality, but only invoke it when language requires it [Dummett] |
8185 | We can't make sense of a world not apprehended by a mind [Dummett] |
8163 | Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts [Dummett] |
8161 | We know we can state facts, with true statements [Dummett] |
8180 | 'That is red or orange' might be considered true, even though 'that is red' and 'that is orange' were not [Dummett] |
10173 | A nominalist might avoid abstract objects by just appealing to mereological sums [Reck/Price] |
8178 | Empirical and a priori knowledge are not distinct, but are extremes of a sliding scale [Dummett] |
8175 | A theory of thought will include propositional attitudes as well as propositions [Dummett] |
8174 | The theories of meaning and understanding are the only routes to an account of thought [Dummett] |
8165 | To 'abstract from' is a logical process, as opposed to the old mental view [Dummett] |
8168 | To know the truth-conditions of a sentence, you must already know the meaning [Dummett] |
8181 | A justificationist theory of meaning leads to the rejection of classical logic [Dummett] |
8182 | Verificationism could be realist, if we imagined the verification by a superhuman power [Dummett] |
8183 | If truths about the past depend on memories and current evidence, the past will change [Dummett] |
8176 | We could only guess the meanings of 'true' and 'false' when sentences were used [Dummett] |
8170 | Sentences are the primary semantic units, because they can say something [Dummett] |
8169 | We can't distinguish a proposition from its content [Dummett] |
23616 | Legal excuses are duress, ignorance, and diminished responsibility [McMahan] |
23606 | Liberty Rights are permissions, and Claim Rights are freedom from intervention [McMahan] |
23620 | A person or state may be attacked if they are responsible for an unjustified threat [McMahan] |
23598 | You (e.g. a police officer) are not liable to attack just because you pose a threat [McMahan] |
23594 | Wars can be unjust, despite a just cause, if they are unnecessary or excessive or of mixed cause [McMahan] |
23597 | Just war theory says all and only persons posing a threat are liable to attack [McMahan] |
23595 | The worst unjustified wars have no aim at all [McMahan] |
23619 | A defensive war is unjust, if it is responding to a just war [McMahan] |
23600 | Proportionality in fighting can't be judged independently of the justice of each side [McMahan] |
23603 | Can an army start an unjust war, and then fight justly to defend their own civilians? [McMahan] |
23611 | Soldiers cannot freely fight in unjust wars, just because they behave well when fighting [McMahan] |
23612 | The law of war differs from criminal law; attacking just combatants is immoral, but legal [McMahan] |
23617 | If the unjust combatants are morally excused they are innocent, so how can they be killed? [McMahan] |
23599 | You don't become a legitimate target, just because you violently resist an unjust attack [McMahan] |
23596 | If all combatants are seen as morally equal, that facilitates starting unjust wars [McMahan] |
23604 | Volunteer soldiers accept the risk of attack, but they don't agree to it, or to their deaths [McMahan] |
23608 | If being part of a big collective relieves soldiers of moral responsibility, why not the leaders too? [McMahan] |
23610 | If soldiers can't refuse to fight in unjust wars, can they choose to fight in just wars? [McMahan] |
23613 | Equality is both sides have permission, or both sides are justified, or one justified the other permitted [McMahan] |
23615 | Fighting unjustly under duress does not justify it, or permit it, but it may excuse it [McMahan] |
23605 | Soldiers cannot know enough facts to evaluate the justice of their war [McMahan] |
23602 | Innocence implies not being morally responsible, rather than merely being guiltless [McMahan] |
23618 | Unconditional surrender can't be demanded, since evil losers still have legitimate conditions [McMahan] |
8186 | Time is the measure of change, so we can't speak of time before all change [Dummett] |
8167 | If Presentism is correct, we cannot even say that the present changes [Dummett] |