111 ideas
15357 | Philosophy is the most general intellectual discipline [Horsten] |
15352 | A definition should allow the defined term to be eliminated [Horsten] |
10882 | Predicative definitions only refer to entities outside the defined collection [Horsten] |
5728 | The concept of truth was originated by the senses [Lucretius] |
15323 | Truth is a property, because the truth predicate has an extension [Horsten] |
15324 | Semantic theories of truth seek models; axiomatic (syntactic) theories seek logical principles [Horsten] |
15374 | Truth has no 'nature', but we should try to describe its behaviour in inferences [Horsten] |
15348 | Propositions have sentence-like structures, so it matters little which bears the truth [Horsten] |
15333 | Modern correspondence is said to be with the facts, not with true propositions [Horsten] |
15337 | The correspondence 'theory' is too vague - about both 'correspondence' and 'facts' [Horsten] |
15334 | The coherence theory allows multiple coherent wholes, which could contradict one another [Horsten] |
15336 | The pragmatic theory of truth is relative; useful for group A can be useless for group B [Horsten] |
15354 | Tarski's hierarchy lacks uniform truth, and depends on contingent factors [Horsten] |
15340 | Tarski Bi-conditional: if you'll assert φ you'll assert φ-is-true - and also vice versa [Horsten] |
15345 | Semantic theories have a regress problem in describing truth in the languages for the models [Horsten] |
15332 | 'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten] |
15346 | Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten] |
15361 | A good theory of truth must be compositional (as well as deriving biconditionals) [Horsten] |
15371 | An axiomatic theory needs to be of maximal strength, while being natural and sound [Horsten] |
15350 | The Naďve Theory takes the bi-conditionals as axioms, but it is inconsistent, and allows the Liar [Horsten] |
15351 | Axiomatic theories take truth as primitive, and propose some laws of truth as axioms [Horsten] |
15367 | By adding truth to Peano Arithmetic we increase its power, so truth has mathematical content! [Horsten] |
15373 | Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [Horsten] |
15330 | Friedman-Sheard theory keeps classical logic and aims for maximum strength [Horsten] |
15331 | Kripke-Feferman has truth gaps, instead of classical logic, and aims for maximum strength [Horsten] |
15325 | Inferential deflationism says truth has no essence because no unrestricted logic governs the concept [Horsten] |
15356 | Deflationism concerns the nature and role of truth, but not its laws [Horsten] |
15344 | Deflationism skips definitions and models, and offers just accounts of basic laws of truth [Horsten] |
15368 | This deflationary account says truth has a role in generality, and in inference [Horsten] |
15358 | Deflationism says truth isn't a topic on its own - it just concerns what is true [Horsten] |
15359 | Deflation: instead of asserting a sentence, we can treat it as an object with the truth-property [Horsten] |
15329 | Nonclassical may accept T/F but deny applicability, or it may deny just T or F as well [Horsten] |
15326 | Doubt is thrown on classical logic by the way it so easily produces the liar paradox [Horsten] |
15341 | Deduction Theorem: ψ only derivable from φ iff φ→ψ are axioms [Horsten] |
15328 | A theory is 'non-conservative' if it facilitates new mathematical proofs [Horsten] |
15349 | It is easier to imagine truth-value gaps (for the Liar, say) than for truth-value gluts (both T and F) [Horsten] |
15366 | Satisfaction is a primitive notion, and very liable to semantical paradoxes [Horsten] |
10884 | A theory is 'categorical' if it has just one model up to isomorphism [Horsten] |
15353 | The first incompleteness theorem means that consistency does not entail soundness [Horsten] |
15355 | Strengthened Liar: 'this sentence is not true in any context' - in no context can this be evaluated [Horsten] |
15364 | English expressions are denumerably infinite, but reals are nondenumerable, so many are unnameable [Horsten] |
10885 | Computer proofs don't provide explanations [Horsten] |
10881 | The concept of 'ordinal number' is set-theoretic, not arithmetical [Horsten] |
15360 | ZFC showed that the concept of set is mathematical, not logical, because of its existence claims [Horsten] |
15369 | Set theory is substantial over first-order arithmetic, because it enables new proofs [Horsten] |
15370 | Predicativism says mathematical definitions must not include the thing being defined [Horsten] |
15338 | We may believe in atomic facts, but surely not complex disjunctive ones? [Horsten] |
15363 | In the supervaluationist account, disjunctions are not determined by their disjuncts [Horsten] |
15362 | If 'Italy is large' lacks truth, so must 'Italy is not large'; but classical logic says it's large or it isn't [Horsten] |
15372 | Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten] |
5729 | If the senses are deceptive, reason, which rests on them, is even worse [Lucretius] |
5702 | The senses are much the best way to distinguish true from false [Lucretius] |
5697 | The only possible standard for settling doubts is the foundation of the senses [Lucretius] |
5727 | Most supposed delusions of the senses are really misinterpretations by the mind [Lucretius] |
5714 | Even simple facts are hard to believe at first hearing [Lucretius] |
5718 | The mind is in the middle of the breast, because there we experience fear and joy [Lucretius] |
5717 | The mind is a part of a man, just like a hand or an eye [Lucretius] |
21387 | The separate elements and capacities of a mind cannot be distinguished [Lucretius] |
5709 | The actions of the mind are not determinate and passive, because atoms can swerve [Lucretius] |
5695 | Only bodies can touch one another [Lucretius] |
5711 | The earth is and always has been an insentient being [Lucretius] |
5712 | Particles may have sensation, but eggs turning into chicks suggests otherwise [Lucretius] |
5719 | The mind moves limbs, wakes the body up, changes facial expressions, which involve touch [Lucretius] |
5724 | Lions, foxes and deer have distinct characters because their minds share in their bodies [Lucretius] |
5713 | You needn't be made of laughing particles to laugh, so why not sensation from senseless seeds? [Lucretius] |
15347 | A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten] |
6611 | One man's meat is another man's poison [Lucretius] |
5730 | Our bodies weren't created to be used; on the contrary, their creation makes a use possible [Lucretius] |
23110 | Human injustice is not a permanent feature of communities [Rawls] |
5726 | The dead are no different from those who were never born [Lucretius] |
15676 | Rawls defends the priority of right over good [Rawls, by Finlayson] |
5705 | Nature only wants two things: freedom from pain, and pleasure [Lucretius] |
4123 | A fair arrangement is one that parties can agree to without knowing how it will benefit them personally [Rawls, by Williams,B] |
21051 | Check your rationality by thinking of your opinion pronounced by the supreme court [Rawls] |
3279 | Utilitarianism inappropriately scales up the individual willingness to make sacrifices [Rawls, by Nagel] |
22406 | The maximisation of happiness must be done fairly [Rawls, by Smart] |
21137 | Rawls rejected cosmopolitanism because it doesn't respect the autonomy of 'peoples' [Rawls, by Shorten] |
3280 | Why does the rational agreement of the 'Original Position' in Rawls make it right? [Nagel on Rawls] |
20552 | The original position models the idea that citizens start as free and equal [Rawls, by Swift] |
18636 | Choose justice principles in ignorance of your own social situation [Rawls] |
18631 | All desirable social features should be equal, unless inequality favours the disadvantaged [Rawls] |
21119 | Power is only legitimate if it is reasonable for free equal citizens to endorse the constitution [Rawls] |
20538 | Utilitarians lump persons together; Rawls somewhat separates them; Nozick wholly separates them [Swift on Rawls] |
9277 | Rawls's account of justice relies on conventional fairness, avoiding all moral controversy [Gray on Rawls] |
23420 | In a pluralist society we can't expect a community united around one conception of the good [Rawls] |
20527 | Liberty Principle: everyone has an equal right to liberties, if compatible with others' liberties [Rawls] |
21018 | The social contract has problems with future generations, national boundaries, disabilities and animals [Rawls, by Nussbaum] |
21041 | Justice concerns not natural distributions, or our born location, but what we do about them [Rawls] |
23583 | If an aggression is unjust, the constraints on how it is fought are much stricter [Rawls] |
5716 | Nature runs the universe by herself without the aid of gods [Lucretius] |
5704 | There can be no centre in infinity [Lucretius] |
5703 | The universe must be limitless, since there could be nothing outside to limit it [Lucretius] |
5693 | Everything is created and fed by nature from atoms, and they return to atoms in death [Lucretius] |
5701 | If an object is infinitely subdivisible, it will be the same as the whole universe [Lucretius] |
5708 | In downward motion, atoms occasionally swerve slightly for no reason [Lucretius] |
17004 | Nothing can break the binding laws of eternity [Lucretius] |
5706 | Atoms move themselves [Lucretius] |
5696 | If there were no space there could be no movement, or even creation [Lucretius] |
5700 | It is quicker to break things up than to assemble them [Lucretius] |
5698 | We can only sense time by means of movement, or its absence [Lucretius] |
5715 | This earth is very unlikely to be the only one created [Lucretius] |
5694 | Nothing can be created by divine power out of nothing [Lucretius] |
5699 | If matter wasn't everlasting, everything would have disappeared by now [Lucretius] |
5707 | The universe can't have been created by gods, because it is too imperfect [Lucretius] |
5710 | Gods are tranquil and aloof, and have no need of or interest in us [Lucretius] |
5731 | Why does Jupiter never hurl lightning from a blue sky? [Lucretius] |
5720 | Spirit is mortal [Lucretius] |
5722 | For a separated spirit to remain sentient it would need sense organs attached to it [Lucretius] |
5725 | An immortal mind couldn't work harmoniously with a mortal body [Lucretius] |
5721 | The mind is very small smooth particles, which evaporate at death [Lucretius] |
5723 | If spirit is immortal and enters us at birth, why don't we remember a previous existence? [Lucretius] |