68 ideas
| 13567 | Ontology should give insight into or an explanation of the world revealed by science [Ellis] |
| 13604 | Real possibility and necessity has the logic of S5, which links equivalence classes of worlds of the same kind [Ellis] |
| 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] |
| 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] |
| 15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
| 15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
| 15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
| 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] |
| 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] |
| 15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
| 15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [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] |
| 13606 | Humean conceptions of reality drive the adoption of extensional logic [Ellis] |
| 15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
| 15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
| 15412 | Models leave out meaning, and just focus on truth values [Burgess] |
| 15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
| 13584 | The extension of a property is a contingent fact, so cannot be the essence of the property [Ellis] |
| 13587 | There is no property of 'fragility', as things are each fragile in a distinctive way [Ellis] |
| 13577 | Typical 'categorical' properties are spatio-temporal, such as shape [Ellis] |
| 9436 | The property of 'being an electron' is not of anything, and only electrons could have it [Ellis] |
| 13582 | 'Being a methane molecule' is not a property - it is just a predicate [Ellis] |
| 13580 | Causal powers must necessarily act the way they do [Ellis] |
| 13598 | Causal powers are often directional (e.g. centripetal, centrifugal, circulatory) [Ellis] |
| 13568 | Basic powers may not be explained by structure, if at the bottom level there is no structure [Ellis] |
| 13586 | Maybe dispositions can be explained by intrinsic properties or structures [Ellis] |
| 13585 | The most fundamental properties of nature (mass, charge, spin ...) all seem to be dispositions [Ellis] |
| 13596 | A causal power is a disposition to produce forces [Ellis] |
| 13599 | Powers are dispositions of the essences of kinds that involve them in causation [Ellis] |
| 13572 | There are 'substantive' (objects of some kind), 'dynamic' (events of some kind) and 'property' universals [Ellis] |
| 13573 | Universals are all types of natural kind [Ellis] |
| 13571 | Scientific essentialism doesn't really need Kripkean individual essences [Ellis] |
| 13578 | The old idea that identity depends on essence and behaviour is rejected by the empiricists [Ellis] |
| 13576 | Necessities are distinguished by their grounds, not their different modalities [Ellis] |
| 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] |
| 13570 | Individual essences necessitate that individual; natural kind essences necessitate kind membership [Ellis] |
| 13607 | If events are unconnected, then induction cannot be solved [Ellis] |
| 13597 | Good explanations unify [Ellis] |
| 13601 | Explanations of particular events are not essentialist, as they don't reveal essential structures [Ellis] |
| 13569 | To give essentialist explanations there have to be natural kinds [Ellis] |
| 13600 | The point of models in theories is not to idealise, but to focus on what is essential [Ellis] |
| 6613 | The natural kinds are objects, processes and properties/relations [Ellis] |
| 13583 | There might be uninstantiated natural kinds, such as transuranic elements which have never occurred [Ellis] |
| 13574 | Natural kinds are distinguished by resting on essences [Ellis] |
| 13575 | If there are borderline cases between natural kinds, that makes them superficial [Ellis] |
| 13595 | Laws don't exist in the world; they are true of the world [Ellis] |
| 6616 | Least action is not a causal law, but a 'global law', describing a global essence [Ellis] |
| 13566 | A proton must have its causal role, because without it it wouldn't be a proton [Ellis] |
| 13579 | What is most distinctive of scientific essentialism is regarding processes as natural kinds [Ellis] |
| 13581 | Scientific essentialism is more concerned with explanation than with identity (Locke, not Kripke) [Ellis] |
| 13594 | The ontological fundamentals are dispositions, and also categorical (spatio-temporal and structural) properties [Ellis] |
| 6615 | A species requires a genus, and its essence includes the essence of the genus [Ellis] |
| 13603 | A primary aim of science is to show the limits of the possible [Ellis] |
| 6614 | A hierarchy of natural kinds is elaborate ontology, but needed to explain natural laws [Ellis] |
| 6612 | Without general principles, we couldn't predict the behaviour of dispositional properties [Ellis] |