72 ideas
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
18826 | 'True at a possibility' means necessarily true if what is said had obtained [Rumfitt] |
18803 | Semantics for propositions: 1) validity preserves truth 2) non-contradition 3) bivalence 4) truth tables [Rumfitt] |
18814 | 'Absolute necessity' would have to rest on S5 [Rumfitt] |
9449 | The plausible Barcan formula implies modality in the actual world [Bird] |
18798 | It is the second-order part of intuitionistic logic which actually negates some classical theorems [Rumfitt] |
18799 | Intuitionists can accept Double Negation Elimination for decidable propositions [Rumfitt] |
18830 | Most set theorists doubt bivalence for the Continuum Hypothesis, but still use classical logic [Rumfitt] |
18843 | The iterated conception of set requires continual increase in axiom strength [Rumfitt] |
18836 | A set may well not consist of its members; the empty set, for example, is a problem [Rumfitt] |
18837 | A set can be determinate, because of its concept, and still have vague membership [Rumfitt] |
18845 | If the totality of sets is not well-defined, there must be doubt about the Power Set Axiom [Rumfitt] |
18815 | Logic is higher-order laws which can expand the range of any sort of deduction [Rumfitt] |
18804 | The case for classical logic rests on its rules, much more than on the Principle of Bivalence [Rumfitt] |
18805 | Classical logic rules cannot be proved, but various lines of attack can be repelled [Rumfitt] |
18827 | If truth-tables specify the connectives, classical logic must rely on Bivalence [Rumfitt] |
18813 | Logical consequence is a relation that can extended into further statements [Rumfitt] |
18808 | Normal deduction presupposes the Cut Law [Rumfitt] |
18840 | When faced with vague statements, Bivalence is not a compelling principle [Rumfitt] |
18802 | In specifying a logical constant, use of that constant is quite unavoidable [Rumfitt] |
18800 | Introduction rules give deduction conditions, and Elimination says what can be deduced [Rumfitt] |
18809 | Logical truths are just the assumption-free by-products of logical rules [Rumfitt] |
18807 | Monotonicity means there is a guarantee, rather than mere inductive support [Rumfitt] |
18842 | Maybe an ordinal is a property of isomorphic well-ordered sets, and not itself a set [Rumfitt] |
18834 | Infinitesimals do not stand in a determinate order relation to zero [Rumfitt] |
18846 | Cantor and Dedekind aimed to give analysis a foundation in set theory (rather than geometry) [Rumfitt] |
9501 | If all existents are causally active, that excludes abstracta and causally isolated objects [Bird] |
9500 | If naturalism refers to supervenience, that leaves necessary entities untouched [Bird] |
9502 | There might be just one fundamental natural property [Bird] |
9477 | Categorical properties are not modally fixed, but change across possible worlds [Bird] |
9490 | The categoricalist idea is that a property is only individuated by being itself [Bird] |
9495 | If we abstractly define a property, that doesn't mean some object could possess it [Bird] |
9492 | Categoricalists take properties to be quiddities, with no essential difference between them [Bird] |
9503 | To name an abundant property is either a Fregean concept, or a simple predicate [Bird] |
14540 | Only real powers are fundamental [Bird, by Mumford/Anjum] |
9450 | If all properties are potencies, and stimuli and manifestation characterise them, there is a regress [Bird] |
9498 | The essence of a potency involves relations, e.g. mass, to impressed force and acceleration [Bird] |
9474 | A disposition is finkish if a time delay might mean the manifestation fizzles out [Bird] |
9475 | A robust pot attached to a sensitive bomb is not fragile, but if struck it will easily break [Bird] |
9499 | Megarian actualists deny unmanifested dispositions [Bird] |
9486 | Why should a universal's existence depend on instantiation in an existing particular? [Bird] |
9472 | Resemblance itself needs explanation, presumably in terms of something held in common [Bird] |
18839 | An object that is not clearly red or orange can still be red-or-orange, which sweeps up problem cases [Rumfitt] |
18838 | The extension of a colour is decided by a concept's place in a network of contraries [Rumfitt] |
9482 | If the laws necessarily imply p, that doesn't give a new 'nomological' necessity [Bird] |
18816 | Metaphysical modalities respect the actual identities of things [Rumfitt] |
9481 | Logical necessitation is not a kind of necessity; George Orwell not being Eric Blair is not a real possibility [Bird] |
18825 | S5 is the logic of logical necessity [Rumfitt] |
18824 | Since possibilities are properties of the world, calling 'red' the determination of a determinable seems right [Rumfitt] |
18828 | If two possibilities can't share a determiner, they are incompatible [Rumfitt] |
9505 | Empiricist saw imaginability and possibility as close, but now they seem remote [Bird] |
18821 | Possibilities are like possible worlds, but not fully determinate or complete [Rumfitt] |
9491 | Haecceitism says identity is independent of qualities and without essence [Bird] |
18831 | Medieval logicians said understanding A also involved understanding not-A [Rumfitt] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
9487 | We can't reject all explanations because of a regress; inexplicable A can still explain B [Bird] |
18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
9493 | We should explain causation by powers, not powers by causation [Bird] |
9494 | Singularism about causes is wrong, as the universals involved imply laws [Bird] |
9507 | Laws are explanatory relationships of things, which supervene on their essences [Bird] |
9488 | Laws are either disposition regularities, or relations between properties [Bird] |
9496 | That other diamonds are hard does not explain why this one is [Bird] |
9479 | Dispositional essentialism says laws (and laws about laws) are guaranteed regularities [Bird] |
9473 | Laws cannot offer unified explanations if they don't involve universals [Bird] |
9484 | If the universals for laws must be instantiated, a vanishing particular could destroy a law [Bird] |
9506 | Salt necessarily dissolves in water, because of the law which makes the existence of salt possible [Bird] |
23713 | Most laws supervene on fundamental laws, which are explained by basic powers [Bird, by Friend/Kimpton-Nye] |
9489 | Essentialism can't use conditionals to explain regularities, because of possible interventions [Bird] |
9504 | The relational view of space-time doesn't cover times and places where things could be [Bird] |