118 ideas
6123 | Empirical investigation can't discover if holes exist, or if two things share a colour [Merricks] |
19215 | Arguers often turn the opponent's modus ponens into their own modus tollens [Merricks] |
14415 | A ground must be about its truth, and not just necessitate it [Merricks] |
14408 | Truthmaker needs truths to be 'about' something, and that is often unclear [Merricks] |
14395 | If a ball changes from red to white, Truthmaker says some thing must make the change true [Merricks] |
14398 | Truthmaker says if an entity is removed, some nonexistence truthmaker must replace it [Merricks] |
14403 | If Truthmaker says each truth is made by the existence of something, the theory had de re modality at is core [Merricks] |
14397 | Truthmaker demands not just a predication, but an existing state of affairs with essential ingredients [Merricks] |
14396 | If 'truth supervenes on being', worlds with the same entities, properties and relations have the same truths [Merricks] |
14400 | If truth supervenes on being, that won't explain why truth depends on being [Merricks] |
14394 | It is implausible that claims about non-existence are about existing things [Merricks] |
14390 | Truthmaker isn't the correspondence theory, because it offers no analysis of truth [Merricks] |
14412 | Speculations about non-existent things are not about existent things, so Truthmaker is false [Merricks] |
14414 | I am a truthmaker for 'that a human exists', but is it about me? [Merricks] |
14418 | Being true is not a relation, it is a primitive monadic property [Merricks] |
14391 | If the correspondence theory is right, then necessary truths must correspond to something [Merricks] |
19205 | 'Snow is white' only contingently expresses the proposition that snow is white [Merricks] |
14419 | Deflationism just says there is no property of being truth [Merricks] |
19209 | Simple Quantified Modal Logc doesn't work, because the Converse Barcan is a theorem [Merricks] |
19208 | The Converse Barcan implies 'everything exists necessarily' is a consequence of 'necessarily, everything exists' [Merricks] |
10073 | There cannot be a set theory which is complete [Smith,P] |
10616 | Second-order arithmetic can prove new sentences of first-order [Smith,P] |
10074 | A 'total function' maps every element to one element in another set [Smith,P] |
10612 | An argument is a 'fixed point' for a function if it is mapped back to itself [Smith,P] |
10605 | Two functions are the same if they have the same extension [Smith,P] |
10075 | A 'partial function' maps only some elements to another set [Smith,P] |
10076 | The 'range' of a function is the set of elements in the output set created by the function [Smith,P] |
10615 | The Comprehension Schema says there is a property only had by things satisfying a condition [Smith,P] |
10595 | A 'theorem' of a theory is a sentence derived from the axioms using the proof system [Smith,P] |
10602 | A 'natural deduction system' has no axioms but many rules [Smith,P] |
10613 | No nice theory can define truth for its own language [Smith,P] |
19207 | Sentence logic maps truth values; predicate logic maps objects and sets [Merricks] |
10079 | A 'bijective' function has one-to-one correspondence in both directions [Smith,P] |
10077 | A 'surjective' ('onto') function creates every element of the output set [Smith,P] |
10078 | An 'injective' ('one-to-one') function creates a distinct output element from each original [Smith,P] |
10070 | If everything that a theory proves is true, then it is 'sound' [Smith,P] |
10086 | Soundness is true axioms and a truth-preserving proof system [Smith,P] |
10596 | A theory is 'sound' iff every theorem is true (usually from true axioms and truth-preservation) [Smith,P] |
10598 | A theory is 'negation complete' if it proves all sentences or their negation [Smith,P] |
10597 | 'Complete' applies both to whole logics, and to theories within them [Smith,P] |
10069 | A theory is 'negation complete' if one of its sentences or its negation can always be proved [Smith,P] |
10609 | Two routes to Incompleteness: semantics of sound/expressible, or syntax of consistency/proof [Smith,P] |
10087 | A theory is 'decidable' if all of its sentences could be mechanically proved [Smith,P] |
10088 | Any consistent, axiomatized, negation-complete formal theory is decidable [Smith,P] |
10080 | 'Effective' means simple, unintuitive, independent, controlled, dumb, and terminating [Smith,P] |
10081 | A set is 'enumerable' is all of its elements can result from a natural number function [Smith,P] |
10083 | A set is 'effectively enumerable' if a computer could eventually list every member [Smith,P] |
10084 | A finite set of finitely specifiable objects is always effectively enumerable (e.g. primes) [Smith,P] |
10085 | The set of ordered pairs of natural numbers <i,j> is effectively enumerable [Smith,P] |
10601 | The thorems of a nice arithmetic can be enumerated, but not the truths (so they're diffferent) [Smith,P] |
10600 | Being 'expressible' depends on language; being 'capture/represented' depends on axioms and proof system [Smith,P] |
10599 | For primes we write (x not= 1 ∧ ∀u∀v(u x v = x → (u = 1 ∨ v = 1))) [Smith,P] |
10610 | The reals contain the naturals, but the theory of reals doesn't contain the theory of naturals [Smith,P] |
10619 | The truths of arithmetic are just true equations and their universally quantified versions [Smith,P] |
10618 | All numbers are related to zero by the ancestral of the successor relation [Smith,P] |
10608 | The number of Fs is the 'successor' of the Gs if there is a single F that isn't G [Smith,P] |
10849 | Baby arithmetic covers addition and multiplication, but no general facts about numbers [Smith,P] |
10850 | Baby Arithmetic is complete, but not very expressive [Smith,P] |
10851 | Robinson Arithmetic 'Q' has basic axioms, quantifiers and first-order logic [Smith,P] |
10852 | Robinson Arithmetic (Q) is not negation complete [Smith,P] |
10068 | Natural numbers have zero, unique successors, unending, no circling back, and no strays [Smith,P] |
10603 | The logic of arithmetic must quantify over properties of numbers to handle induction [Smith,P] |
10604 | Incompleteness results in arithmetic from combining addition and successor with multiplication [Smith,P] |
10848 | Multiplication only generates incompleteness if combined with addition and successor [Smith,P] |
14393 | The totality state is the most plausible truthmaker for negative existential truths [Merricks] |
6143 | Prolonged events don't seem to endure or exist at any particular time [Merricks] |
6135 | A crumbling statue can't become vague, because vagueness is incoherent [Merricks] |
10617 | The 'ancestral' of a relation is a new relation which creates a long chain of the original relation [Smith,P] |
14413 | Some properties seem to be primitive, but others can be analysed [Merricks] |
6145 | Intrinsic properties are those an object still has even if only that object exists [Merricks] |
14416 | An object can have a disposition when the revelant conditional is false [Merricks] |
6124 | I say that most of the objects of folk ontology do not exist [Merricks] |
6134 | Is swimming pool water an object, composed of its mass or parts? [Merricks] |
14392 | Fregeans say 'hobbits do not exist' is just 'being a hobbit' is not exemplified [Merricks] |
6125 | We can eliminate objects without a commitment to simples [Merricks] |
14229 | Merricks agrees that there are no composite objects, but offers a different semantics [Merricks, by Liggins] |
6142 | The 'folk' way of carving up the world is not intrinsically better than quite arbitrary ways [Merricks] |
14472 | If atoms 'arranged baseballwise' break a window, that analytically entails that a baseball did it [Merricks, by Thomasson] |
14469 | Overdetermination: the atoms do all the causing, so the baseball causes no breakage [Merricks] |
6137 | Clay does not 'constitute' a statue, as they have different persistence conditions (flaking, squashing) [Merricks] |
6141 | There is no visible difference between statues, and atoms arranged statuewise [Merricks] |
6127 | 'Unrestricted composition' says any two things can make up a third thing [Merricks] |
6131 | Composition as identity is false, as identity is never between a single thing and many things [Merricks] |
6132 | Composition as identity is false, as it implies that things never change their parts [Merricks] |
6130 | 'Composition' says things are their parts; 'constitution' says a whole substance is an object [Merricks] |
6138 | It seems wrong that constitution entails that two objects are wholly co-located [Merricks] |
6128 | Objects decompose (it seems) into non-overlapping parts that fill its whole region [Merricks] |
14410 | You believe you existed last year, but your segment doesn't, so they have different beliefs [Merricks] |
19214 | In twinning, one person has the same origin as another person [Merricks] |
6136 | Eliminativism about objects gives the best understanding of the Sorites paradox [Merricks] |
14417 | Counterfactuals aren't about actuality, so they lack truthmakers or a supervenience base [Merricks] |
6133 | If my counterpart is happy, that is irrelevant to whether I 'could' have been happy [Merricks] |
14402 | If 'Fido is possibly black' depends on Fido's counterparts, then it has no actual truthmaker [Merricks] |
6150 | The 'warrant' for a belief is what turns a true belief into knowledge [Merricks] |
20653 | Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson] |
6144 | You hold a child in your arms, so it is not mental substance, or mental state, or software [Merricks] |
6140 | Maybe the word 'I' can only refer to persons [Merricks] |
6149 | Free will and determinism are incompatible, since determinism destroys human choice [Merricks] |
6148 | Human organisms can exercise downward causation [Merricks] |
6146 | Before Creation it is assumed that God still had many many mental properties [Merricks] |
6147 | The hypothesis of solipsism doesn't seem to be made incoherent by the nature of mental properties [Merricks] |
19217 | I don't accept that if a proposition is directly about an entity, it has a relation to the entity [Merricks] |
19203 | A sentence's truth conditions depend on context [Merricks] |
19200 | Propositions are standardly treated as possible worlds, or as structured [Merricks] |
19206 | 'Cicero is an orator' represents the same situation as 'Tully is an orator', so they are one proposition [Merricks] |
19202 | Propositions are necessary existents which essentially (but inexplicably) represent things [Merricks] |
19204 | True propositions existed prior to their being thought, and might never be thought [Merricks] |
19210 | The standard view of propositions says they never change their truth-value [Merricks] |
19201 | Propositions can be 'about' an entity, but that doesn't make the entity a constituent of it [Merricks] |
19211 | Early Russell says a proposition is identical with its truthmaking state of affairs [Merricks] |
19212 | Unity of the proposition questions: what unites them? can the same constituents make different ones? [Merricks] |
19213 | We want to explain not just what unites the constituents, but what unites them into a proposition [Merricks] |
17960 | Eternalism says all times are equally real, and future and past objects and properties are real [Merricks] |
17961 | Growing block has a subjective present and a growing edge - but these could come apart [Merricks, by PG] |
14407 | Presentist should deny there is a present time, and just say that things 'exist' [Merricks] |
14411 | Maybe only presentism allows change, by now having a property, and then lacking it [Merricks] |
14406 | Presentists say that things have existed and will exist, not that they are instantaneous [Merricks] |
14405 | How can a presentist explain an object's having existed? [Merricks] |