78 ideas
19635 | Hegel produced modern optimism; he failed to grasp that consciousness never progresses [Hegel, by Cioran] |
13466 | We are all post-Kantians, because he set the current agenda for philosophy [Hart,WD] |
8215 | Hegel was the last philosopher of the Book [Hegel, by Derrida] |
13477 | The problems are the monuments of philosophy [Hart,WD] |
16011 | Hegel doesn't storm the heavens like the giants, but works his way up by syllogisms [Kierkegaard on Hegel] |
5433 | For Hegel, things are incomplete, and contain external references in their own nature [Hegel, by Russell] |
3301 | On the continent it is generally believed that metaphysics died with Hegel [Benardete,JA on Hegel] |
13515 | To study abstract problems, some knowledge of set theory is essential [Hart,WD] |
19661 | Making sufficient reason an absolute devalues the principle of non-contradiction [Hegel, by Meillassoux] |
20952 | Rather than in three stages, Hegel presented his dialectic as 'negation of the negation' [Hegel, by Bowie] |
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] |
21777 | Negation of negation doubles back into a self-relationship [Hegel, by Houlgate] |
4568 | If 'Queen of England' does not refer if there is no queen, its meaning can't refer if there is one [Cooper,DE] |
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] |
13474 | Euclid has a unique parallel, spherical geometry has none, and saddle geometry has several [Hart,WD] |
13471 | Mathematics makes existence claims, but philosophers usually say those are never analytic [Hart,WD] |
5645 | The dialectical opposition of being and nothing is resolved in passing to the concept of becoming [Hegel, by Scruton] |
5646 | Hegel gives an ontological proof of the existence of everything [Hegel, by Scruton] |
13488 | Mass words do not have plurals, or numerical adjectives, or use 'fewer' [Hart,WD] |
21755 | For Hegel, categories shift their form in the course of history [Hegel, by Houlgate] |
21754 | Our concepts and categories disclose the world, because we are part of the world [Hegel, by Houlgate] |
22079 | Hegel said Kant's fixed categories actually vary with culture and era [Hegel, by Houlgate] |
4574 | If some peoples do not have categories like time or cause, they can't be essential features of rationality [Cooper,DE] |
13480 | Fregean self-evidence is an intrinsic property of basic truths, rules and definitions [Hart,WD] |
9225 | Hegel reputedly claimed to know a priori that there are five planets [Hegel, by Field,H] |
13476 | The failure of key assumptions in geometry, mereology and set theory throw doubt on the a priori [Hart,WD] |
4573 | If it is claimed that language correlates with culture, we must be able to identify the two independently [Cooper,DE] |
4575 | A person's language doesn't prove their concepts, but how are concepts deduced apart from language? [Cooper,DE] |
4561 | Many sentences set up dispositions which are irrelevant to the meanings of the sentences [Cooper,DE] |
13475 | The Fregean concept of GREEN is a function assigning true to green things, and false to the rest [Hart,WD] |
4564 | I can meaningfully speculate that humans may have experiences currently impossible for us [Cooper,DE] |
4565 | The verification principle itself seems neither analytic nor verifiable [Cooper,DE] |
4563 | 'How now brown cow?' is used for elocution, but this says nothing about its meaning [Cooper,DE] |
4562 | Most people know how to use the word "Amen", but they do not know what it means [Cooper,DE] |
4566 | Any thesis about reference is also a thesis about what exists to be referred to [Cooper,DE] |
4571 | Reference need not be a hit-or-miss affair [Cooper,DE] |
4572 | If predicates name things, that reduces every sentence to a mere list of names [Cooper,DE] |
4576 | An analytic truth is one which becomes a logical truth when some synonyms have been replaced [Cooper,DE] |
21758 | Humans have no fixed identity, but produce and reveal their shifting identity in history [Hegel, by Houlgate] |
20414 | Hegel's Absolute Spirit is the union of human rational activity at a moment, and whatever that sustains [Hegel, by Eldridge] |
3909 | Society isn’t founded on a contract, since contracts presuppose a society [Hegel, by Scruton] |
4347 | When man wills the natural, it is no longer natural [Hegel] |
4188 | Hegel's entire philosophy is nothing but a monstrous amplification of the ontological proof [Schopenhauer on Hegel] |
6686 | Hegel said he was offering an encyclopaedic rationalisation of Christianity [Hegel, by Graham] |