68 ideas
17774 | Definitions make our intuitions mathematically useful [Mayberry] |
17773 | Proof shows that it is true, but also why it must be true [Mayberry] |
23000 | Vicious regresses force you to another level; non-vicious imply another level [Baron/Miller] |
17795 | Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry] |
17796 | There is a semi-categorical axiomatisation of set-theory [Mayberry] |
17800 | The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry] |
17801 | The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry] |
17803 | Limitation of size is part of the very conception of a set [Mayberry] |
17786 | The mainstream of modern logic sees it as a branch of mathematics [Mayberry] |
17788 | First-order logic only has its main theorems because it is so weak [Mayberry] |
17791 | Only second-order logic can capture mathematical structure up to isomorphism [Mayberry] |
17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
17790 | No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry] |
17779 | 'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry] |
17778 | Axiomatiation relies on isomorphic structures being essentially the same [Mayberry] |
17780 | 'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry] |
17789 | No logic which can axiomatise arithmetic can be compact or complete [Mayberry] |
23024 | A traveller takes a copy of a picture into the past, gives it the artist, who then creates the original! [Baron/Miller] |
17784 | Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry] |
17782 | Greek quantities were concrete, and ratio and proportion were their science [Mayberry] |
17781 | Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry] |
17799 | Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry] |
17797 | Cantor extended the finite (rather than 'taming the infinite') [Mayberry] |
17775 | If proof and definition are central, then mathematics needs and possesses foundations [Mayberry] |
17776 | The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry] |
17777 | Foundations need concepts, definition rules, premises, and proof rules [Mayberry] |
17804 | Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry] |
17792 | 1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry] |
17793 | It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry] |
17794 | Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry] |
17802 | We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry] |
17805 | Set theory is not just another axiomatised part of mathematics [Mayberry] |
23008 | Grounding is intended as a relation that fits dependences between things [Baron/Miller] |
17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
23018 | How does a changing object retain identity or have incompatible properties over time? [Baron/Miller] |
7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
23011 | Modern accounts of causation involve either processes or counterfactuals [Baron/Miller] |
23013 | The main process theory of causation says it is transference of mass, energy, momentum or charge [Baron/Miller] |
23014 | If causes are processes, what is causation by omission? (Distinguish legal from scientific causes?) [Baron/Miller] |
23015 | The counterfactual theory of causation handles the problem no matter what causes actually are [Baron/Miller] |
23016 | Counterfactual theories struggle with pre-emption by a causal back-up system [Baron/Miller] |
23009 | There is no second 'law' of thermodynamics; it just reflects probabilities of certain microstates [Baron/Miller] |
23002 | In relativity space and time depend on one's motion, but spacetime gives an invariant metric [Baron/Miller] |
22988 | The block universe theory says entities of all times exist, and time is the B-series [Baron/Miller] |
22991 | How can we know this is the present moment, if other times are real? [Baron/Miller] |
22992 | If we are actually in the past then we shouldn't experience time passing [Baron/Miller] |
22994 | Erzatz Presentism allows the existence of other times, with only the present 'actualised' [Baron/Miller] |
22998 | How do presentists explain relations between things existing at different times? [Baron/Miller] |
23017 | Presentism needs endurantism, because other theories imply most of the object doesn't exist [Baron/Miller] |
23023 | How can presentists move to the next future moment, if that doesn't exist? [Baron/Miller] |
22995 | Most of the sciences depend on the concept of time [Baron/Miller] |
22993 | For abstractionists past times might still exist, althought their objects don't [Baron/Miller] |
23001 | The error theory of time's passage says it is either a misdescription or a false inference [Baron/Miller] |
22999 | It is meaningless to measure the rate of time using time itself, and without a rate there is no flow [Baron/Miller] |
22986 | The C-series rejects A and B, and just sees times as order by betweenness, without direction [Baron/Miller] |
22996 | The A-series has to treat being past, present or future as properties [Baron/Miller] |
23007 | The B-series can have a direction, as long as it does not arise from temporal flow [Baron/Miller] |
23003 | Static theories cannot account for time's obvious asymmetry, so time must be dynamic [Baron/Miller] |
23004 | The direction of time is either primitive, or reducible to something else [Baron/Miller] |
23005 | The kaon does not seem to be time-reversal invariant, unlike the rest of nature [Baron/Miller] |
23006 | Maybe the past is just the direction of decreasing entropy [Baron/Miller] |
23010 | We could explain time's direction by causation: past is the direction of causes, future of effects [Baron/Miller] |
22989 | Static time theory presents change as one property at t1, and a different property at t2 [Baron/Miller] |
23020 | If a time traveller kills his youthful grandfather, he both exists and fails to exist [Baron/Miller] |
23022 | Presentism means there no existing past for a time traveller to visit [Baron/Miller] |
22987 | The past (unlike the future) is fixed, along with truths about it, by the existence of past objects [Baron/Miller] |
22990 | The moving spotlight says entities can have properties of being present, past or future [Baron/Miller] |
22997 | The present moment is a matter of existence, not of acquiring a property [Baron/Miller] |