80 ideas
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] |
14562 | A process is unified as an expression of a collection of causal powers [Mumford/Anjum] |
14541 | Events are essentially changes; property exemplifications are just states of affairs [Mumford/Anjum] |
14553 | Weak emergence is just unexpected, and strong emergence is beyond all deduction [Mumford/Anjum] |
14538 | Powers explain properties, causes, modality, events, and perhaps even particulars [Mumford/Anjum] |
14555 | Powers offer no more explanation of nature than laws do [Mumford/Anjum] |
14557 | Powers are not just basic forces, since they combine to make new powers [Mumford/Anjum] |
14583 | Dispositionality is a natural selection function, picking outcomes from the range of possibilities [Mumford/Anjum] |
14536 | We say 'power' and 'disposition' are equivalent, but some say dispositions are manifestable [Mumford/Anjum] |
14584 | The simple conditional analysis of dispositions doesn't allow for possible prevention [Mumford/Anjum] |
14582 | Might dispositions be reduced to normativity, or to intentionality? [Mumford/Anjum] |
14542 | If statue and clay fall and crush someone, the event is not overdetermined [Mumford/Anjum] |
14535 | Pandispositionalists say structures are clusters of causal powers [Mumford/Anjum] |
14561 | Perdurantism imposes no order on temporal parts, so sequences of events are contingent [Mumford/Anjum] |
14579 | Dispositionality is the core modality, with possibility and necessity as its extreme cases [Mumford/Anjum] |
14580 | Dispositions may suggest modality to us - as what might not have been, and what could have been [Mumford/Anjum] |
14552 | Relations are naturally necessary when they are generated by the essential mechanisms of the world [Mumford/Anjum] |
14578 | Possibility might be non-contradiction, or recombinations of the actual, or truth in possible worlds [Mumford/Anjum] |
14549 | Maybe truths are necessitated by the facts which are their truthmakers [Mumford/Anjum] |
14585 | We have more than five senses; balance and proprioception, for example [Mumford/Anjum] |
14576 | Smoking disposes towards cancer; smokers without cancer do not falsify this claim [Mumford/Anjum] |
14551 | If causation were necessary, the past would fix the future, and induction would be simple [Mumford/Anjum] |
14571 | The only full uniformities in nature occur from the essences of fundamental things [Mumford/Anjum] |
14570 | Nature is not completely uniform, and some regular causes sometimes fail to produce their effects [Mumford/Anjum] |
14569 | It is tempting to think that only entailment provides a full explanation [Mumford/Anjum] |
14568 | A structure won't give a causal explanation unless we know the powers of the structure [Mumford/Anjum] |
14556 | Strong emergence seems to imply top-down causation, originating in consciousness [Mumford/Anjum] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
14566 | Causation by absence is not real causation, but part of our explanatory practices [Mumford/Anjum] |
14577 | Causation may not be transitive. Does a fire cause itself to be extinguished by the sprinklers? [Mumford/Anjum] |
14563 | Causation is the passing around of powers [Mumford/Anjum] |
14587 | We take causation to be primitive, as it is hard to see how it could be further reduced [Mumford/Anjum] |
14533 | Causation doesn't have two distinct relata; it is a single unfolding process [Mumford/Anjum] |
14558 | A collision is a process, which involves simultaneous happenings, but not instantaneous ones [Mumford/Anjum] |
14559 | Does causation need a third tying ingredient, or just two that meet, or might there be a single process? [Mumford/Anjum] |
14565 | Sugar dissolving is a process taking time, not one event and then another [Mumford/Anjum] |
14567 | Privileging one cause is just an epistemic or pragmatic matter, not an ontological one [Mumford/Anjum] |
14537 | Coincidence is conjunction without causation; smoking causing cancer is the reverse [Mumford/Anjum] |
14573 | Occasionally a cause makes no difference (pre-emption, perhaps) so the counterfactual is false [Mumford/Anjum] |
14572 | Is a cause because of counterfactual dependence, or is the dependence because there is a cause? [Mumford/Anjum] |
14574 | Cases of preventing a prevention may give counterfactual dependence without causation [Mumford/Anjum] |
14539 | Nature can be interfered with, so a cause never necessitates its effects [Mumford/Anjum] |
14550 | We assert causes without asserting that they necessitate their effects [Mumford/Anjum] |
14546 | Necessary causation should survive antecedent strengthening, but no cause can always survive that [Mumford/Anjum] |
14575 | A 'ceteris paribus' clause implies that a conditional only has dispositional force [Mumford/Anjum] |
14548 | There may be necessitation in the world, but causation does not supply it [Mumford/Anjum] |
14554 | Laws are nothing more than descriptions of the behaviour of powers [Mumford/Anjum] |
14564 | If laws are equations, cause and effect must be simultaneous (or the law would be falsified)! [Mumford/Anjum] |