65 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] |
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] |
15945 | Second-order set theory just adds a version of Replacement that quantifies over functions [Lavine] |
15914 | An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one [Lavine] |
15921 | Collections of things can't be too big, but collections by a rule seem unlimited in size [Lavine] |
15937 | Those who reject infinite collections also want to reject the Axiom of Choice [Lavine] |
15936 | The Power Set is just the collection of functions from one collection to another [Lavine] |
15899 | Replacement was immediately accepted, despite having very few implications [Lavine] |
15930 | Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets [Lavine] |
15920 | Pure collections of things obey Choice, but collections defined by a rule may not [Lavine] |
15898 | The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine] |
15919 | The 'logical' notion of class has some kind of definition or rule to characterise the class [Lavine] |
15900 | The iterative conception of set wasn't suggested until 1947 [Lavine] |
15931 | The iterative conception needs the Axiom of Infinity, to show how far we can iterate [Lavine] |
15932 | The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs [Lavine] |
15933 | Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement [Lavine] |
15913 | A collection is 'well-ordered' if there is a least element, and all of its successors can be identified [Lavine] |
15926 | Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine] |
15934 | Mathematical proof by contradiction needs the law of excluded middle [Lavine] |
15907 | Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine] |
15942 | Every rational number, unlike every natural number, is divisible by some other number [Lavine] |
15922 | For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine] |
18250 | Cauchy gave a necessary condition for the convergence of a sequence [Lavine] |
15904 | The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine] |
15912 | Counting results in well-ordering, and well-ordering makes counting possible [Lavine] |
15949 | The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine] |
15947 | The infinite is extrapolation from the experience of indefinitely large size [Lavine] |
15940 | The intuitionist endorses only the potential infinite [Lavine] |
15909 | 'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine] |
15915 | Ordinals are basic to Cantor's transfinite, to count the sets [Lavine] |
15917 | Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine] |
15918 | Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine] |
15929 | Set theory will found all of mathematics - except for the notion of proof [Lavine] |
15935 | Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine] |
15928 | Intuitionism rejects set-theory to found mathematics [Lavine] |
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] |
16277 | Logically impossible is metaphysically impossible, but logically possible is not metaphysically possible [Maudlin] |
16249 | A counterfactual antecedent commands the redescription of a selected moment [Maudlin] |
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] |
467 | A virtue is a combination of intelligence, strength and luck [Ion] |
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] |
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] |