86 ideas
16241 | The metaphysics of nature should focus on physics [Maudlin] |
16257 | Kant survives in seeing metaphysics as analysing our conceptual system, which is a priori [Maudlin] |
16276 | Wide metaphysical possibility may reduce metaphysics to analysis of fantasies [Maudlin] |
1502 | Parmenides was much more cautious about accepting ideas than his predecessors [Simplicius on Parmenides] |
16244 | If the universe is profligate, the Razor leads us astray [Maudlin] |
16255 | The Razor rightly prefers one cause of multiple events to coincidences of causes [Maudlin] |
15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
15409 | All occurrences of variables in atomic formulas are free [Burgess] |
15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
15412 | Models leave out meaning, and just focus on truth values [Burgess] |
15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
448 | No necessity could produce Being either later or earlier, so it must exist absolutely or not at all [Parmenides] |
447 | Being must be eternal and uncreated, and hence it is timeless [Parmenides] |
449 | Being is not divisible, since it is all alike [Parmenides] |
1503 | There is no such thing as nothing [Parmenides] |
445 | The realm of necessary non-existence cannot be explored, because it is unknowable [Parmenides] |
21820 | Parmenides at least saw Being as the same as Nous, and separate from the sensed realm [Parmenides, by Plotinus] |
452 | All our concepts of change and permanence are just names, not the truth [Parmenides] |
16243 | The Humean view is wrong; laws and direction of time are primitive, and atoms are decided by physics [Maudlin] |
16271 | Lewis says it supervenes on the Mosaic, but actually thinks the Mosaic is all there is [Maudlin] |
16273 | If the Humean Mosaic is ontological bedrock, there can be no explanation of its structure [Maudlin] |
16275 | The 'spinning disc' is just impossible, because there cannot be 'homogeneous matter' [Maudlin] |
16258 | To get an ontology from ontological commitment, just add that some theory is actually true [Maudlin] |
16259 | Naïve translation from natural to formal language can hide or multiply the ontology [Maudlin] |
16253 | A property is fundamental if two objects can differ in only that respect [Maudlin] |
16263 | Fundamental physics seems to suggest there are no such things as properties [Maudlin] |
16260 | Existence of universals may just be decided by acceptance, or not, of second-order logic [Maudlin] |
1504 | Something must be unchanging to make recognition and knowledge possible [Aristotle on Parmenides] |
15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
444 | The first way of enquiry involves necessary existence [Parmenides] |
16277 | Logically impossible is metaphysically impossible, but logically possible is not metaphysically possible [Maudlin] |
15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
450 | Necessity sets limits on being, in order to give it identity [Parmenides] |
15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
16249 | A counterfactual antecedent commands the redescription of a selected moment [Maudlin] |
451 | Thinking implies existence, because thinking depends on it [Parmenides] |
1506 | Parmenides treats perception and intellectual activity as the same [Theophrastus on Parmenides] |
3058 | Only reason can prove the truth of facts [Parmenides] |
16254 | Induction leaps into the unknown, but usually lands safely [Maudlin] |
16245 | Laws should help explain the things they govern, or that manifest them [Maudlin] |
555 | People who say that the cosmos is one forget that they must explain movement [Aristotle on Parmenides] |
5081 | There could be movement within one thing, as there is within water [Aristotle on Parmenides] |
1509 | The one can't be divisible, because if it was it could be infinitely divided down to nothing [Parmenides, by Simplicius] |
20900 | Defenders of the One say motion needs the void - but that is not part of Being [Parmenides, by Aristotle] |
226 | The one is without any kind of motion [Parmenides] |
1505 | Reason sees reality as one, the senses see it as many [Aristotle on Parmenides] |
453 | Reality is symmetrical and balanced, like a sphere, with no reason to be greater one way rather than another [Parmenides] |
1792 | He taught that there are two elements, fire the maker, and earth the matter [Parmenides, by Diog. Laertius] |
16248 | Evaluating counterfactuals involves context and interests [Maudlin] |
16250 | We don't pick a similar world from many - we construct one possibility from the description [Maudlin] |
16268 | The counterfactual is ruined if some other cause steps in when the antecedent fails [Maudlin] |
16267 | If we know the cause of an event, we seem to assent to the counterfactual [Maudlin] |
16269 | If the effect hadn't occurred the cause wouldn't have happened, so counterfactuals are two-way [Maudlin] |
16247 | Laws are primitive, so two indiscernible worlds could have the same laws [Maudlin] |
16272 | Fundamental laws say how nature will, or might, evolve from some initial state [Maudlin] |
16242 | Laws of nature are ontological bedrock, and beyond analysis [Maudlin] |
16251 | 'Humans with prime house numbers are mortal' is not a law, because not a natural kind [Maudlin] |
16270 | If laws are just regularities, then there have to be laws [Maudlin] |
5115 | It is feeble-minded to look for explanations of everything being at rest [Aristotle on Parmenides] |
13217 | The void can't exist, and without the void there can't be movement or separation [Parmenides, by Aristotle] |
16264 | I believe the passing of time is a fundamental fact about the world [Maudlin] |
16265 | If time passes, presumably it passes at one second per second [Maudlin] |
16266 | There is one ordered B series, but an infinitude of A series, depending on when the present is [Maudlin] |
22918 | What could have triggered the beginning [of time and being]? [Parmenides] |
1794 | He was the first to discover the identity of the Morning and Evening Stars [Parmenides, by Diog. Laertius] |
1791 | He was the first person to say the earth is spherical [Parmenides, by Diog. Laertius] |