74 ideas
13466 | We are all post-Kantians, because he set the current agenda for philosophy [Hart,WD] |
21887 | Derrida focuses on other philosophers, rather than on science [Derrida] |
21888 | Philosophy is just a linguistic display [Derrida] |
13477 | The problems are the monuments of philosophy [Hart,WD] |
21896 | Philosophy aims to build foundations for thought [Derrida, by May] |
21893 | Philosophy is necessarily metaphorical, and its writing is aesthetic [Derrida] |
13515 | To study abstract problems, some knowledge of set theory is essential [Hart,WD] |
21892 | Interpretations can be interpreted, so there is no original 'meaning' available [Derrida] |
20925 | Hermeneutics blunts truth, by conforming it to the interpreter [Derrida, by Zimmermann,J] |
20934 | Hermeneutics is hostile, trying to overcome the other person's difference [Derrida, by Zimmermann,J] |
21895 | Structuralism destroys awareness of dynamic meaning [Derrida] |
21934 | The idea of being as persistent presence, and meaning as conscious intelligibility, are self-destructive [Derrida, by Glendinning] |
21883 | Sincerity can't be verified, so fiction infuses speech, and hence reality also [Derrida] |
21882 | Sentences are contradictory, as they have opposite meanings in some contexts [Derrida] |
21881 | We aim to explore the limits of expression (as in Mallarmé's poetry) [Derrida] |
4756 | Derrida says that all truth-talk is merely metaphor [Derrida, by Engel] |
21877 | True thoughts are inaccessible, in the subconscious, prior to speech or writing [Derrida] |
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] |
21878 | Names have a subjective aspect, especially the role of our own name [Derrida] |
21889 | 'I' is the perfect name, because it denotes without description [Derrida] |
21879 | Even Kripke can't explain names; the word is the thing, and the thing is the word [Derrida] |
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] |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
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] |
13488 | Mass words do not have plurals, or numerical adjectives, or use 'fewer' [Hart,WD] |
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] |
21890 | Heidegger showed that passing time is the key to consciousness [Derrida] |
21880 | 'Tacit theory' controls our thinking (which is why Freud is important) [Derrida] |
13475 | The Fregean concept of GREEN is a function assigning true to green things, and false to the rest [Hart,WD] |
21894 | Madness and instability ('the demonic hyperbole') lurks in all language [Derrida] |
21886 | Meanings depend on differences and contrasts [Derrida] |
21930 | For Aristotle all proper nouns must have a single sense, which is the purpose of language [Derrida] |
21884 | Capacity for repetitions is the hallmark of language [Derrida] |
21935 | The sign is only conceivable as a movement between elusive presences [Derrida] |
21933 | Writing functions even if the sender or the receiver are absent [Derrida, by Glendinning] |
21931 | 'Dissemination' is opposed to polysemia, since that is irreducible, because of multiple understandings [Derrida, by Glendinning] |
21885 | Words exist in 'spacing', so meanings are never synchronic except in writing [Derrida] |
21891 | The good is implicitly violent (against evil), so there is no pure good [Derrida] |