50 ideas
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] |
15105 | F(x) walked into a bar. The barman said.. [Sommers,W] |
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] |
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] |
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] |
12408 | Sartre to Waitress: Coffee with no cream, please... [Sommers,W] |
12397 | Said Plato: 'The things that we feel... [Sommers,W] |
15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
12407 | Barman to Descartes: Would you like another drink?... [Sommers,W] |
12399 | There was a young student called Fred... [Sommers,W] |
20963 | A philosopher and his wife are out for a drive... [Sommers,W] |
12402 | ..But if he's a student of Berkeley... [Sommers,W] |
12409 | The philosopher Berkeley once said.. [Sommers,W] |
12404 | Dear Sir, Your astonishment's odd.... [Sommers,W] |
12403 | There once was a man who said: 'God... [Sommers,W] |
14694 | "My dog's got synaesthesia." How does he smell? ..... [Sommers,W] |
12401 | A toper who spies in the distance... [Sommers,W] |
12410 | There once was a man who said 'Damn!... [Sommers,W] |
9392 | How do behaviourists greet each other? [Sommers,W] |
12405 | 'If you're aristocratic,' said Nietzsche... [Sommers,W] |
9391 | Why do anarchists drink herbal tea? [Sommers,W] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
12400 | Cries the maid: 'You must marry me Hume!'... [Sommers,W] |
16527 | Causation - we all thought we knew it/ Till Hume came along and saw through it/…. [Sommers,W] |
17592 | The barman called 'Time!', and Augustine said..... [Sommers,W] |
15208 | The past, present and future walked into a bar.... [Sommers,W] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |