64 ideas
1597 | Thales was the first western thinker to believe the arché was intelligible [Roochnik on Thales] |
14415 | A ground must be about its truth, and not just necessitate it [Merricks] |
14408 | Truthmaker needs truths to be 'about' something, and that is often unclear [Merricks] |
14395 | If a ball changes from red to white, Truthmaker says some thing must make the change true [Merricks] |
14398 | Truthmaker says if an entity is removed, some nonexistence truthmaker must replace it [Merricks] |
14403 | If Truthmaker says each truth is made by the existence of something, the theory had de re modality at is core [Merricks] |
14397 | Truthmaker demands not just a predication, but an existing state of affairs with essential ingredients [Merricks] |
14396 | If 'truth supervenes on being', worlds with the same entities, properties and relations have the same truths [Merricks] |
14400 | If truth supervenes on being, that won't explain why truth depends on being [Merricks] |
14394 | It is implausible that claims about non-existence are about existing things [Merricks] |
14390 | Truthmaker isn't the correspondence theory, because it offers no analysis of truth [Merricks] |
14412 | Speculations about non-existent things are not about existent things, so Truthmaker is false [Merricks] |
14414 | I am a truthmaker for 'that a human exists', but is it about me? [Merricks] |
14418 | Being true is not a relation, it is a primitive monadic property [Merricks] |
14391 | If the correspondence theory is right, then necessary truths must correspond to something [Merricks] |
14419 | Deflationism just says there is no property of being truth [Merricks] |
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] |
15947 | The infinite is extrapolation from the experience of indefinitely large size [Lavine] |
15949 | The theory of infinity must rest on our inability to distinguish between very large sizes [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] |
14393 | The totality state is the most plausible truthmaker for negative existential truths [Merricks] |
14413 | Some properties seem to be primitive, but others can be analysed [Merricks] |
14416 | An object can have a disposition when the revelant conditional is false [Merricks] |
14392 | Fregeans say 'hobbits do not exist' is just 'being a hobbit' is not exemplified [Merricks] |
14410 | You believe you existed last year, but your segment doesn't, so they have different beliefs [Merricks] |
14417 | Counterfactuals aren't about actuality, so they lack truthmakers or a supervenience base [Merricks] |
3013 | Nothing is stronger than necessity, which rules everything [Thales, by Diog. Laertius] |
14402 | If 'Fido is possibly black' depends on Fido's counterparts, then it has no actual truthmaker [Merricks] |
1494 | Thales said water is the first principle, perhaps from observing that food is moist [Thales, by Aristotle] |
1713 | Thales must have thought soul causes movement, since he thought magnets have soul [Thales, by Aristotle] |
14407 | Presentist should deny there is a present time, and just say that things 'exist' [Merricks] |
14411 | Maybe only presentism allows change, by now having a property, and then lacking it [Merricks] |
14406 | Presentists say that things have existed and will exist, not that they are instantaneous [Merricks] |
14405 | How can a presentist explain an object's having existed? [Merricks] |
1742 | Thales said the gods know our wrong thoughts as well as our evil actions [Thales, by Diog. Laertius] |