73 ideas
14227 | We could refer to tables as 'xs that are arranged tablewise' [Inwagen] |
15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
10662 | Mereology is 'nihilistic' (just atoms) or 'universal' (no restrictions on what is 'whole') [Inwagen, by Varzi] |
15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
17587 | The 'Law' of Excluded Middle needs all propositions to be definitely true or definitely false [Inwagen] |
15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
17558 | Variables are just like pronouns; syntactic explanations get muddled over dummy letters [Inwagen] |
15409 | All occurrences of variables in atomic formulas are free [Burgess] |
15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
15412 | Models leave out meaning, and just focus on truth values [Burgess] |
15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
17583 | There are no heaps [Inwagen] |
17578 | I reject talk of 'stuff', and treat it in terms of particles [Inwagen] |
17582 | Singular terms can be vague, because they can contain predicates, which can be vague [Inwagen] |
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] |
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] |
15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
17572 | Actuality proves possibility, but that doesn't explain how it is possible [Inwagen] |
17579 | Counterparts reduce counterfactual identity to problems about similarity relations [Inwagen] |
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] |
541 | Virtue comes more from habit than character [Critias] |
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] |
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] |
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] |
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] |
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] |
17573 | There is no reason to think that mere existence is a valuable thing [Inwagen] |
542 | Fear of the gods was invented to discourage secret sin [Critias] |