65 ideas
16943 | Philosophy is continuous with science, and has no external vantage point [Quine] |
19504 | My modus ponens might be your modus tollens [Pritchard,D] |
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] |
15898 | The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine] |
15920 | Pure collections of things obey Choice, but collections defined by a rule may not [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] |
16949 | Klein summarised geometry as grouped together by transformations [Quine] |
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] |
16939 | Mass terms just concern spread, but other terms involve both spread and individuation [Quine] |
16948 | Once we know the mechanism of a disposition, we can eliminate 'similarity' [Quine] |
16945 | We judge things to be soluble if they are the same kind as, or similar to, things that do dissolve [Quine] |
19503 | An improbable lottery win can occur in a nearby possible world [Pritchard,D] |
19505 | Moore begs the question, or just offers another view, or uses 'know' wrongly [Pritchard,D, by PG] |
19499 | We can have evidence for seeing a zebra, but no evidence for what is entailed by that [Pritchard,D] |
19500 | Favouring: an entailment will give better support for the first belief than reason to deny the second [Pritchard,D] |
19502 | Maybe knowledge just needs relevant discriminations among contrasting cases [Pritchard,D] |
19498 | Epistemic internalism usually says justification must be accessible by reflection [Pritchard,D] |
19506 | Externalism is better than internalism in dealing with radical scepticism [Pritchard,D] |
19496 | Disjunctivism says perceptual justification must be both factual and known by the agent [Pritchard,D] |
19497 | Metaphysical disjunctivism says normal perceptions and hallucinations are different experiences [Pritchard,D] |
19495 | Epistemic externalism struggles to capture the idea of epistemic responsibility [Pritchard,D] |
19501 | We assess error against background knowledge, but that is just what radical scepticism challenges [Pritchard,D] |
19507 | Radical scepticism is merely raised, and is not a response to worrying evidence [Pritchard,D] |
16944 | Science is common sense, with a sophisticated method [Quine] |
16941 | Induction relies on similar effects following from each cause [Quine] |
16940 | Induction is just more of the same: animal expectations [Quine] |
16933 | Grue is a puzzle because the notions of similarity and kind are dubious in science [Quine] |
16934 | General terms depend on similarities among things [Quine] |
16938 | To learn yellow by observation, must we be told to look at the colour? [Quine] |
8486 | Standards of similarity are innate, and the spacing of qualities such as colours can be mapped [Quine] |
16947 | Similarity is just interchangeability in the cosmic machine [Quine] |
16932 | Projectible predicates can be universalised about the kind to which they refer [Quine] |
7375 | Quine probably regrets natural kinds now being treated as essences [Quine, by Dennett] |
16935 | If similarity has no degrees, kinds cannot be contained within one another [Quine] |
16936 | Comparative similarity allows the kind 'colored' to contain the kind 'red' [Quine] |
16937 | You can't base kinds just on resemblance, because chains of resemblance are a muddle [Quine] |
16942 | It is hard to see how regularities could be explained [Quine] |