122 ideas
15357 | Philosophy is the most general intellectual discipline [Horsten] |
224 | When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato] |
232 | Opposites are as unlike as possible [Plato] |
8937 | Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato] |
15352 | A definition should allow the defined term to be eliminated [Horsten] |
15324 | Semantic theories of truth seek models; axiomatic (syntactic) theories seek logical principles [Horsten] |
15323 | Truth is a property, because the truth predicate has an extension [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] |
15373 | Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [Horsten] |
15346 | Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten] |
15371 | An axiomatic theory needs to be of maximal strength, while being natural and sound [Horsten] |
15332 | 'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten] |
15361 | A good theory of truth must be compositional (as well as deriving biconditionals) [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] |
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] |
15344 | Deflationism skips definitions and models, and offers just accounts of basic laws of truth [Horsten] |
15356 | Deflationism concerns the nature and role of truth, but not its laws [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] |
15353 | The first incompleteness theorem means that consistency does not entail soundness [Horsten] |
13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
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] |
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] |
16150 | One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato] |
15370 | Predicativism says mathematical definitions must not include the thing being defined [Horsten] |
229 | The one was and is and will be and was becoming and is becoming and will become [Plato] |
21821 | Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus] |
221 | Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato] |
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] |
223 | If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato] |
227 | You must always mean the same thing when you utter the same name [Plato] |
210 | It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato] |
220 | The concept of a master includes the concept of a slave [Plato] |
211 | If admirable things have Forms, maybe everything else does as well [Plato] |
219 | If absolute ideas existed in us, they would cease to be absolute [Plato] |
228 | Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato] |
16151 | Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M] |
218 | Participation is not by means of similarity, so we are looking for some other method of participation [Plato] |
215 | If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato] |
212 | The whole idea of each Form must be found in each thing which participates in it [Plato] |
213 | Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato] |
216 | If things are made alike by participating in something, that thing will be the absolute idea [Plato] |
217 | Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato] |
214 | If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato] |
15851 | Parts must belong to a created thing with a distinct form [Plato] |
15846 | In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V] |
15849 | Plato says only a one has parts, and a many does not [Plato, by Harte,V] |
15850 | Anything which has parts must be one thing, and parts are of a one, not of a many [Plato] |
13259 | It seems that the One must be composed of parts, which contradicts its being one [Plato] |
15847 | Two things relate either as same or different, or part of a whole, or the whole of the part [Plato] |
5937 | The goodness of opinions depends on their grounds, and corresponding degrees of conviction [Ross] |
15372 | Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten] |
5936 | Knowledge is superior to opinion because it is certain [Ross] |
5927 | I prefer the causal theory to sense data, because sensations are events, not apprehensions [Ross] |
5940 | Two goods may be comparable, although they are not commensurable [Ross] |
5924 | Identical objects must have identical value [Ross] |
15347 | A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten] |
5933 | Aesthetic enjoyment combines pleasure with insight [Ross] |
5928 | Beauty is neither objective nor subjective, but a power of producing certain mental events [Ross] |
5911 | Moral duties are as fundamental to the universe as the axioms of mathematics [Ross] |
5926 | The beauty of a patch of colour might be the most important fact about it [Ross] |
7259 | Ross said moral principles are self-evident from the facts, but not from pure thought [Ross, by Dancy,J] |
5913 | The moral convictions of thoughtful educated people are the raw data of ethics [Ross] |
5920 | Value is held to be either a quality, or a relation (usually between a thing and a mind) [Ross] |
5923 | The arguments for value being an objective or a relation fail, so it appears to be a quality [Ross] |
5918 | The thing is intrinsically good if it would be good when nothing else existed [Ross] |
5930 | All things being equal, we all prefer the virtuous to be happy, not the vicious [Ross] |
5922 | An instrumentally good thing might stay the same, but change its value because of circumstances [Ross] |
5921 | We can ask of pleasure or beauty whether they are valuable, but not of goodness [Ross] |
5932 | The four goods are: virtue, pleasure, just allocation of pleasure, and knowledge [Ross] |
5910 | The three intrinsic goods are virtue, knowledge and pleasure [Ross] |
5898 | 'Right' and 'good' differ in meaning, as in a 'right action' and a 'good man' [Ross] |
5899 | If there are two equally good acts, they may both be right, but neither a duty [Ross] |
5904 | In the past 'right' just meant what is conventionally accepted [Ross] |
5919 | Goodness is a wider concept than just correct ethical conduct [Ross] |
5941 | Motives decide whether an action is good, and what is done decides whether it was right [Ross] |
5938 | Virtue is superior to pleasure, as pleasure is never a duty, but goodness is [Ross] |
5931 | All other things being equal, a universe with more understanding is better [Ross] |
5939 | Morality is not entirely social; a good moral character should love truth [Ross] |
5905 | We clearly value good character or understanding, as well as pleasure [Ross] |
5929 | No one thinks it doesn't matter whether pleasure is virtuously or viciously acquired [Ross] |
5906 | Promise-keeping is bound by the past, and is not concerned with consequences [Ross] |
18622 | Promises create a new duty to a particular person; they aren't just a strategy to achieve well-being [Ross] |
5908 | Prima facie duties rest self-evidently on particular circumstance [Ross] |
5917 | People lose their rights if they do not respect the rights of others [Ross] |
5900 | We should do our duty, but not from a sense of duty [Ross] |
5942 | We like people who act from love, but admire more the people who act from duty [Ross] |
5909 | Be faithful, grateful, just, beneficent, non-malevolent, and improve yourself [Ross, by PG] |
5914 | An act may be described in innumerable ways [Ross] |
5912 | We should use money to pay debts before giving to charity [Ross] |
5916 | Rights were originally legal, and broadened to include other things [Ross] |
222 | Only a great person can understand the essence of things, and an even greater person can teach it [Plato] |
5915 | Rights can be justly claimed, so animals have no rights, as they cannot claim any [Ross] |
225 | The unlimited has no shape and is endless [Plato] |
233 | Some things do not partake of the One [Plato] |
2062 | The only movement possible for the One is in space or in alteration [Plato] |
231 | Everything partakes of the One in some way [Plato] |
234 | We couldn't discuss the non-existence of the One without knowledge of it [Plato] |