64 ideas
| 10354 | Correspondence could be with other beliefs, rather than external facts [Kusch] |
| 10353 | Tarskians distinguish truth from falsehood by relations between members of sets [Kusch] |
| 10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
| 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] |
| 10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
| 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] |
| 10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
| 10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
| 10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
| 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] |
| 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] |
| 10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
| 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] |
| 10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
| 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] |
| 10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
| 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] |
| 10337 | We can have knowledge without belief, if others credit us with knowledge [Kusch] |
| 10357 | Methodological Solipsism assumes all ideas could be derived from one mind [Kusch] |
| 10339 | Foundations seem utterly private, even from oneself at a later time [Kusch] |
| 10331 | Testimony is reliable if it coheres with evidence for a belief, and with other beliefs [Kusch] |
| 10338 | The coherentist restricts the space of reasons to the realm of beliefs [Kusch] |
| 10340 | Individualistic coherentism lacks access to all of my beliefs, or critical judgement of my assessment [Kusch] |
| 10345 | Individual coherentism cannot generate the necessary normativity [Kusch] |
| 10350 | Cultures decide causal routes, and they can be critically assessed [Kusch] |
| 10343 | Process reliabilism has been called 'virtue epistemology', resting on perception, memory, reason [Kusch] |
| 10341 | Justification depends on the audience and one's social role [Kusch] |
| 10334 | Testimony is an area in which epistemology meets ethics [Kusch] |
| 10336 | Powerless people are assumed to be unreliable, even about their own lives [Kusch] |
| 10324 | Testimony does not just transmit knowledge between individuals - it actually generates knowledge [Kusch] |
| 10327 | Some want to reduce testimony to foundations of perceptions, memories and inferences [Kusch] |
| 10329 | Testimony won't reduce to perception, if perception depends on social concepts and categories [Kusch] |
| 10330 | A foundation is what is intelligible, hence from a rational source, and tending towards truth [Kusch] |
| 10325 | Vindicating testimony is an expression of individualism [Kusch] |
| 10335 | Myths about lonely genius are based on epistemological individualism [Kusch] |
| 10323 | Communitarian Epistemology says 'knowledge' is a social status granted to groups of people [Kusch] |
| 10348 | Private justification is justification to imagined other people [Kusch] |
| 10349 | To be considered 'an individual' is performed by a society [Kusch] |
| 10344 | Our experience may be conceptual, but surely not the world itself? [Kusch] |
| 10358 | Often socialising people is the only way to persuade them [Kusch] |
| 10333 | Communitarianism in epistemology sees the community as the primary knower [Kusch] |
| 10351 | Natural kinds are social institutions [Kusch] |
| 10332 | Omniscience is incoherent, since knowledge is a social concept [Kusch] |