66 ideas
22611 | Metaphysics can criticise interpretations of science theories, and give good feedback [Ingthorsson] |
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] |
22609 | Philosophers accepted first-order logic, because they took science to be descriptive, not explanatory [Ingthorsson] |
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] |
22629 | Basic processes are said to be either physical, or organic, or psychological [Ingthorsson] |
22633 | Indirect realists are cautious about the manifest image, and prefer the scientific image [Ingthorsson] |
22606 | Neo-Humeans say there are no substantial connections between anything [Ingthorsson] |
22631 | Properties are said to be categorical qualities or non-qualitative dispositions [Ingthorsson] |
22632 | Physics understands the charge of an electron as a power, not as a quality [Ingthorsson] |
22627 | Compound objects are processes, insofar as change is essential to them [Ingthorsson] |
22613 | Most materialist views postulate smallest indivisible components which are permanent [Ingthorsson] |
22612 | Endurance and perdurance just show the consequences of A or B series time [Ingthorsson] |
22625 | Science suggests causal aspects of the constitution and persistance of objects [Ingthorsson] |
22620 | If causation involves production, that needs persisting objects [Ingthorsson] |
22636 | Every philosophical theory must be true in some possible world, so the ontology is hopeless [Ingthorsson] |
22638 | Worlds may differ in various respects, but no overall similarity of worlds is implied [Ingthorsson] |
21971 | Transcendental philosophy is the subject becoming the originator of unified reality [Kant] |
22605 | Humeans describe the surface of causation, while powers accounts aim at deeper explanations [Ingthorsson] |
22607 | Time and space are not causal, but they determine natural phenomena [Ingthorsson] |
22608 | Casuation is the transmission of conserved quantities between causal processes [Ingthorsson] |
22614 | Interventionist causal theory says it gets a reliable result whenever you manipulate it [Ingthorsson] |
22621 | Causation as transfer only works for asymmetric interactions [Ingthorsson] |
22639 | Causal events are always reciprocal, and there is no distinction of action and reaction [Ingthorsson] |
22615 | One effect cannot act on a second effect in causation, because the second doesn't yet exist [Ingthorsson] |
22616 | Empiricists preferred events to objects as the relata, because they have observable motions [Ingthorsson] |
22617 | Science now says all actions are reciprocal, not unidirectional [Ingthorsson] |
22619 | Causes are not agents; the whole interaction is the cause, and the changed compound is the effect [Ingthorsson] |
22635 | People only accept the counterfactual when they know the underlying cause [Ingthorsson] |
22634 | Counterfactuals don't explain causation, but causation can explain counterfactuals [Ingthorsson] |
22637 | Counterfactual theories are false in possible worlds where causation is actual [Ingthorsson] |
22624 | A cause can fail to produce its normal effect, by prevention, pre-emption, finks or antidotes [Ingthorsson] |
22622 | Any process can go backwards or forwards in time without violating the basic laws of physics [Ingthorsson] |
22618 | In modern physics the first and second laws of motion (unlike the third) fail at extremes [Ingthorsson] |
22630 | If particles have decay rates, they can't really be elementary, in the sense of indivisible [Ingthorsson] |
22610 | It is difficult to handle presentism in first-order logic [Ingthorsson] |