93 ideas
18495 | The best philosophers I know are the best people I know [Heil] |
13466 | We are all post-Kantians, because he set the current agenda for philosophy [Hart,WD] |
13477 | The problems are the monuments of philosophy [Hart,WD] |
18494 | Using a technical vocabulary actually prevents discussion of the presuppositions [Heil] |
18506 | Questions of explanation should not be confused with metaphyics [Heil] |
18535 | Without abstraction we couldn't think systematically [Heil] |
13515 | To study abstract problems, some knowledge of set theory is essential [Hart,WD] |
18534 | Truth relates truthbearers to truthmakers [Heil] |
18531 | Philosophers of the past took the truthmaking idea for granted [Heil] |
18509 | Not all truths need truthmakers - mathematics and logic seem to be just true [Heil] |
13469 | Tarski showed how we could have a correspondence theory of truth, without using 'facts' [Hart,WD] |
13504 | Truth for sentences is satisfaction of formulae; for sentences, either all sequences satisfy it (true) or none do [Hart,WD] |
13503 | A first-order language has an infinity of T-sentences, which cannot add up to a definition of truth [Hart,WD] |
13500 | Conditional Proof: infer a conditional, if the consequent can be deduced from the antecedent [Hart,WD] |
13502 | ∃y... is read as 'There exists an individual, call it y, such that...', and not 'There exists a y such that...' [Hart,WD] |
13456 | Set theory articulates the concept of order (through relations) [Hart,WD] |
13497 | Nowadays ZFC and NBG are the set theories; types are dead, and NF is only useful for the whole universe [Hart,WD] |
13443 | ∈ relates across layers, while ⊆ relates within layers [Hart,WD] |
13442 | Without the empty set we could not form a∩b without checking that a and b meet [Hart,WD] |
13493 | In the modern view, foundation is the heart of the way to do set theory [Hart,WD] |
13495 | Foundation Axiom: an nonempty set has a member disjoint from it [Hart,WD] |
13462 | With the Axiom of Choice every set can be well-ordered [Hart,WD] |
13461 | We can choose from finite and evident sets, but not from infinite opaque ones [Hart,WD] |
13516 | If we accept that V=L, it seems to settle all the open questions of set theory [Hart,WD] |
13441 | Naïve set theory has trouble with comprehension, the claim that every predicate has an extension [Hart,WD] |
13494 | The iterative conception may not be necessary, and may have fixed points or infinitely descending chains [Hart,WD] |
13460 | 'Well-ordering' must have a least member, so it does the natural numbers but not the integers [Hart,WD] |
13458 | A partial ordering becomes 'total' if any two members of its field are comparable [Hart,WD] |
13457 | A 'partial ordering' is irreflexive and transitive; the sets are ordered, but not the subsets [Hart,WD] |
13490 | Von Neumann defines α<β as α∈β [Hart,WD] |
13481 | Maybe sets should be rethought in terms of the even more basic categories [Hart,WD] |
9455 | Maybe proper names have the content of fixing a thing's category [Bealer] |
9454 | The four leading theories of definite descriptions are Frege's, Russell's, Evans's, and Prior's [Bealer] |
13506 | The universal quantifier can't really mean 'all', because there is no universal set [Hart,WD] |
13513 | Models are ways the world might be from a first-order point of view [Hart,WD] |
13505 | Model theory studies how set theory can model sets of sentences [Hart,WD] |
13511 | Model theory is mostly confined to first-order theories [Hart,WD] |
13512 | Modern model theory begins with the proof of Los's Conjecture in 1962 [Hart,WD] |
13496 | First-order logic is 'compact': consequences of a set are consequences of a finite subset [Hart,WD] |
13484 | Berry's Paradox: we succeed in referring to a number, with a term which says we can't do that [Hart,WD] |
13482 | The Burali-Forti paradox is a crisis for Cantor's ordinals [Hart,WD] |
13507 | The machinery used to solve the Liar can be rejigged to produce a new Liar [Hart,WD] |
13459 | The less-than relation < well-orders, and partially orders, and totally orders the ordinal numbers [Hart,WD] |
13463 | There are at least as many infinite cardinals as transfinite ordinals (because they will map) [Hart,WD] |
13491 | The axiom of infinity with separation gives a least limit ordinal ω [Hart,WD] |
13492 | Von Neumann's ordinals generalise into the transfinite better, because Zermelo's ω is a singleton [Hart,WD] |
13446 | 19th century arithmetization of analysis isolated the real numbers from geometry [Hart,WD] |
13509 | We can establish truths about infinite numbers by means of induction [Hart,WD] |
18518 | Infinite numbers are qualitatively different - they are not just very large numbers [Heil] |
13474 | Euclid has a unique parallel, spherical geometry has none, and saddle geometry has several [Hart,WD] |
18500 | How could structures be mathematical truthmakers? Maths is just true, without truthmakers [Heil] |
13471 | Mathematics makes existence claims, but philosophers usually say those are never analytic [Hart,WD] |
18539 | Our categories lack the neat arrangement needed for reduction [Heil] |
13488 | Mass words do not have plurals, or numerical adjectives, or use 'fewer' [Hart,WD] |
18505 | Fundamental ontology aims at the preconditions for any true theory [Heil] |
18499 | Our quantifications only reveal the truths we accept; the ontology and truthmakers are another matter [Heil] |
18512 | Ontology aims to give the fundamental categories of being [Heil] |
18508 | Most philosophers now (absurdly) believe that relations fully exist [Heil] |
18532 | If causal relations are power manifestations, that makes them internal relations [Heil] |
18510 | We need properties to explain how the world works [Heil] |
18522 | Categorical properties were introduced by philosophers as actual properties, not if-then properties [Heil] |
18513 | Emergent properties will need emergent substances to bear them [Heil] |
18540 | Predicates only match properties at the level of fundamentals [Heil] |
18533 | In Fa, F may not be a property of a, but a determinable, satisfied by some determinate [Heil] |
18511 | Properties have causal roles which sets can't possibly have [Heil] |
18523 | Are all properties powers, or are there also qualities, or do qualities have the powers? [Heil] |
18524 | Properties are both qualitative and dispositional - they are powerful qualities [Heil] |
18498 | Abstract objects wouldn't be very popular without the implicit idea of truthmakers [Heil] |
18507 | Substances bear properties, so must be simple, and not consist of further substances [Heil] |
18515 | Spatial parts are just regions, but objects depend on and are made up of substantial parts [Heil] |
18516 | A 'gunky' universe would literally have no parts at all [Heil] |
18514 | Many wholes can survive replacement of their parts [Heil] |
18517 | Dunes depend on sand grains, but line segments depend on the whole line [Heil] |
18502 | If basic physics has natures, then why not reality itself? That would then found the deepest necessities [Heil] |
18496 | If possible worlds are just fictions, they can't be truthmakers for modal judgements [Heil] |
13480 | Fregean self-evidence is an intrinsic property of basic truths, rules and definitions [Hart,WD] |
13476 | The failure of key assumptions in geometry, mereology and set theory throw doubt on the a priori [Hart,WD] |
18525 | Mental abstraction does not make what is abstracted mind-dependent [Heil] |
18504 | Only particulars exist, and generality is our mode of presentation [Heil] |
18503 | You can think of tomatoes without grasping what they are [Heil] |
18538 | Non-conscious thought may be unlike conscious thought [Heil] |
18537 | Linguistic thought is just as imagistic as non-linguistic thought [Heil] |
13475 | The Fregean concept of GREEN is a function assigning true to green things, and false to the rest [Hart,WD] |
18536 | The subject-predicate form reflects reality [Heil] |
9452 | Propositions might be reduced to functions (worlds to truth values), or ordered sets of properties and relations [Bealer] |
9453 | Sentences saying the same with the same rigid designators may still express different propositions [Bealer] |
9451 | Modal logic and brain science have reaffirmed traditional belief in propositions [Bealer] |
18497 | Many reject 'moral realism' because they can't see any truthmakers for normative judgements [Heil] |
18519 | If there were infinite electrons, they could vanish without affecting total mass-energy [Heil] |
18526 | We should focus on actual causings, rather than on laws and causal sequences [Heil] |
18527 | Probabilistic causation is not a weak type of cause; it is just a probability of there being a cause [Heil] |
18520 | Electrons are treated as particles, but they lose their individuality in relations [Heil] |
18501 | Maybe the universe is fine-tuned because it had to be, despite plans by God or Nature? [Heil] |