106 ideas
| 14227 | We could refer to tables as 'xs that are arranged tablewise' [Inwagen] |
| 10987 | Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read] |
| 11004 | Necessity is provability in S4, and true in all worlds in S5 [Read] |
| 11018 | There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read] |
| 11011 | Same say there are positive, negative and neuter free logics [Read] |
| 11020 | Realisms like the full Comprehension Principle, that all good concepts determine sets [Read] |
| 8972 | What in the real world could ground the distinction between the sets {A,{A,B}} and {B,{A,B}}? [Inwagen] |
| 10662 | Mereology is 'nihilistic' (just atoms) or 'universal' (no restrictions on what is 'whole') [Inwagen, by Varzi] |
| 14187 | If logic is topic-neutral that means it delves into all subjects, rather than having a pure subject matter [Read] |
| 10986 | Not all validity is captured in first-order logic [Read] |
| 10972 | The non-emptiness of the domain is characteristic of classical logic [Read] |
| 11024 | Semantics must precede proof in higher-order logics, since they are incomplete [Read] |
| 10985 | We should exclude second-order logic, precisely because it captures arithmetic [Read] |
| 14188 | Not all arguments are valid because of form; validity is just true premises and false conclusion being impossible [Read] |
| 14182 | If the logic of 'taller of' rests just on meaning, then logic may be the study of merely formal consequence [Read] |
| 14183 | Maybe arguments are only valid when suppressed premises are all stated - but why? [Read] |
| 10970 | A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read] |
| 10984 | Logical consequence isn't just a matter of form; it depends on connections like round-square [Read] |
| 14184 | In modus ponens the 'if-then' premise contributes nothing if the conclusion follows anyway [Read] |
| 17587 | The 'Law' of Excluded Middle needs all propositions to be definitely true or definitely false [Inwagen] |
| 14186 | Logical connectives contain no information, but just record combination relations between facts [Read] |
| 17558 | Variables are just like pronouns; syntactic explanations get muddled over dummy letters [Inwagen] |
| 10973 | A theory is logically closed, which means infinite premisses [Read] |
| 11007 | Quantifiers are second-order predicates [Read] |
| 10978 | In second-order logic the higher-order variables range over all the properties of the objects [Read] |
| 10971 | A logical truth is the conclusion of a valid inference with no premisses [Read] |
| 10988 | Any first-order theory of sets is inadequate [Read] |
| 10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
| 10975 | Compactness does not deny that an inference can have infinitely many premisses [Read] |
| 10977 | Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read] |
| 10976 | Compactness makes consequence manageable, but restricts expressive power [Read] |
| 11014 | Self-reference paradoxes seem to arise only when falsity is involved [Read] |
| 17583 | There are no heaps [Inwagen] |
| 11025 | Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read] |
| 10979 | Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read] |
| 10980 | Second-order arithmetic covers all properties, ensuring categoricity [Read] |
| 10997 | Von Neumann numbers are helpful, but don't correctly describe numbers [Read] |
| 17578 | I reject talk of 'stuff', and treat it in terms of particles [Inwagen] |
| 11016 | Would a language without vagueness be usable at all? [Read] |
| 17582 | Singular terms can be vague, because they can contain predicates, which can be vague [Inwagen] |
| 11013 | Identities and the Indiscernibility of Identicals don't work with supervaluations [Read] |
| 11019 | Supervaluations say there is a cut-off somewhere, but at no particular place [Read] |
| 11012 | A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read] |
| 17556 | Material objects are in space and time, move, have a surface and mass, and are made of some stuff [Inwagen] |
| 8264 | Maybe table-shaped particles exist, but not tables [Inwagen, by Lowe] |
| 10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
| 17565 | Nihilism says composition between single things is impossible [Inwagen] |
| 14228 | If there are no tables, but tables are things arranged tablewise, the denial of tables is a contradiction [Liggins on Inwagen] |
| 14468 | Actions by artefacts and natural bodies are disguised cooperations, so we don't need them [Inwagen] |
| 17571 | Every physical thing is either a living organism or a simple [Inwagen] |
| 17562 | The statue and lump seem to share parts, but the statue is not part of the lump [Inwagen] |
| 17574 | If you knead clay you make an infinite series of objects, but they are rearrangements, not creations [Inwagen] |
| 17531 | I assume matter is particulate, made up of 'simples' [Inwagen] |
| 17560 | If contact causes composition, do two colliding balls briefly make one object? [Inwagen] |
| 17561 | If bricks compose a house, that is at least one thing, but it might be many things [Inwagen] |
| 17566 | I think parthood involves causation, and not just a reasonably stable spatial relationship [Inwagen] |
| 14230 | We can deny whole objects but accept parts, by referring to them as plurals within things [Inwagen, by Liggins] |
| 17557 | Special Composition Question: when is a thing part of something? [Inwagen] |
| 17564 | The essence of a star includes the released binding energy which keeps it from collapse [Inwagen] |
| 17575 | The persistence of artifacts always covertly involves intelligent beings [Inwagen] |
| 17577 | When an electron 'leaps' to another orbit, is the new one the same electron? [Inwagen] |
| 17589 | If you reject transitivity of vague identity, there is no Ship of Theseus problem [Inwagen] |
| 17588 | We should talk of the transitivity of 'identity', and of 'definite identity' [Inwagen] |
| 11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
| 10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
| 10989 | The standard view of conditionals is that they are truth-functional [Read] |
| 11017 | Some people even claim that conditionals do not express propositions [Read] |
| 14185 | Conditionals are just a shorthand for some proof, leaving out the details [Read] |
| 17572 | Actuality proves possibility, but that doesn't explain how it is possible [Inwagen] |
| 10983 | Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read] |
| 10982 | How can modal Platonists know the truth of a modal proposition? [Read] |
| 10996 | Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read] |
| 10981 | A possible world is a determination of the truth-values of all propositions of a domain [Read] |
| 17579 | Counterparts reduce counterfactual identity to problems about similarity relations [Inwagen] |
| 11000 | If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read] |
| 17590 | A merely possible object clearly isn't there, so that is a defective notion [Inwagen] |
| 17591 | Merely possible objects must be consistent properties, or haecceities [Inwagen] |
| 7439 | The qualities involved in sensations are entirely intentional [Anscombe, by Armstrong] |
| 10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
| 8353 | Freedom involves acting according to an idea [Anscombe] |
| 8352 | To believe in determinism, one must believe in a system which determines events [Anscombe] |
| 6981 | Determinism clashes with free will, as the past determines action, and is beyond our control [Inwagen, by Jackson] |
| 11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
| 10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |
| 20041 | Intentional actions are those which are explained by giving the reason for so acting [Anscombe] |
| 7101 | Virtue theory needs an external standard to judge behaviour and character [Inwagen, by Statman] |
| 8070 | It would be better to point to failings of character, than to moral wrongness of actions [Anscombe] |
| 8065 | 'Ought' and 'right' are survivals from earlier ethics, and should be jettisoned [Anscombe] |
| 8069 | Between Aristotle and us, a Judaeo-Christian legal conception of ethics was developed [Anscombe] |
| 8351 | With diseases we easily trace a cause from an effect, but we cannot predict effects [Anscombe] |
| 4777 | The word 'cause' is an abstraction from a group of causal terms in a language (scrape, push..) [Anscombe] |
| 10363 | Causation is relative to how we describe the primary relata [Anscombe, by Schaffer,J] |
| 8350 | Since Mill causation has usually been explained by necessary and sufficient conditions [Anscombe] |
| 17563 | The strong force pulls, but also pushes apart if nucleons get too close together [Inwagen] |
| 17559 | Is one atom a piece of gold, or is a sizable group of atoms required? [Inwagen] |
| 17586 | At the lower level, life trails off into mere molecular interaction [Inwagen] |
| 17584 | Some events are only borderline cases of lives [Inwagen] |
| 17569 | Unlike waves, lives are 'jealous'; it is almost impossible for them to overlap [Inwagen] |
| 17580 | One's mental and other life is centred on the brain, unlike any other part of the body [Inwagen] |
| 17568 | A tumour may spread a sort of life, but it is not a life, or an organism [Inwagen] |
| 17581 | Being part of an organism's life is a matter of degree, and vague [Inwagen] |
| 17570 | The chemical reactions in a human life involve about sixteen elements [Inwagen] |
| 17585 | Life is vague at both ends, but could it be totally vague? [Inwagen] |
| 17567 | A flame is like a life, but not nearly so well individuated [Inwagen] |
| 17576 | If God were to 'reassemble' my atoms of ten years ago, the result would certainly not be me [Inwagen] |
| 17573 | There is no reason to think that mere existence is a valuable thing [Inwagen] |