49 ideas
| 2956 | There is nothing so obvious that a philosopher cannot be found to deny it [Lockwood] |
| 2963 | There may only be necessary and sufficient conditions (and counterfactuals) because we intervene in the world [Lockwood] |
| 2958 | No one has ever succeeded in producing an acceptable non-trivial analysis of anything [Lockwood] |
| 2959 | If something is described in two different ways, is that two facts, or one fact presented in two ways? [Lockwood] |
| 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] |
| 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] |
| 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] |
| 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] |
| 2969 | How does a direct realist distinguish a building from Buckingham Palace? [Lockwood] |
| 12155 | Statements of 'relative identity' are really statements of resemblance [Perry] |
| 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] |
| 2970 | Dogs seem to have beliefs, and beliefs require concepts [Lockwood] |
| 2961 | Empiricism is a theory of meaning as well as of knowledge [Lockwood] |
| 2960 | Commonsense realism must account for the similarity of genuine perceptions and known illusions [Lockwood] |
| 2952 | A 1988 estimate gave the brain 3 x 10-to-the-14 synaptic junctions [Lockwood] |
| 2964 | How come unconscious states also cause behaviour? [Lockwood] |
| 2951 | Could there be unconscious beliefs and desires? [Lockwood] |
| 2953 | Fish may operate by blindsight [Lockwood] |
| 2967 | We might even learn some fundamental physics from introspection [Lockwood] |
| 2966 | Can phenomenal qualities exist unsensed? [Lockwood] |
| 2955 | If mental events occur in time, then relativity says they are in space [Lockwood] |
| 2950 | Only logical positivists ever believed behaviourism [Lockwood] |
| 2954 | Identity theory likes the identity of lightning and electrical discharges [Lockwood] |
| 2971 | Perhaps logical positivism showed that there is no dividing line between science and metaphysics [Lockwood] |
| 2962 | Maybe causation is a form of rational explanation, not an observation or a state of mind [Lockwood] |
| 2949 | We have the confused idea that time is a process of change [Lockwood] |