53 ideas
| 12619 | We have no successful definitions, because they all use indefinable words [Fodor] |
| 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] |
| 12620 | If 'exist' is ambiguous in 'chairs and numbers exist', that mirrors the difference between chairs and numbers [Fodor] |
| 12613 | Empiricists use dispositions reductively, as 'possibility of sensation' or 'possibility of experimental result' [Fodor] |
| 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] |
| 12617 | Associationism can't explain how truth is preserved [Fodor] |
| 12615 | Mental representations are the old 'Ideas', but without images [Fodor] |
| 6650 | Fodor is now less keen on the innateness of concepts [Fodor, by Lowe] |
| 12618 | It is essential to the concept CAT that it be satisfied by cats [Fodor] |
| 12614 | I prefer psychological atomism - that concepts are independent of epistemic capacities [Fodor] |
| 12621 | Definable concepts have constituents, which are necessary, individuate them, and demonstrate possession [Fodor] |
| 12622 | Many concepts lack prototypes, and complex prototypes aren't built from simple ones [Fodor] |
| 12623 | The theory theory can't actually tell us what concepts are [Fodor] |
| 12616 | English has no semantic theory, just associations between sentences and thoughts [Fodor] |
| 3926 | The human heart has a natural concern for public good [Hume] |
| 3929 | No moral theory is of any use if it doesn't serve the interests of the individual concerned [Hume] |
| 3925 | Personal Merit is the possession of useful or agreeable mental qualities [Hume] |
| 3922 | Justice only exists to support society [Hume] |
| 23560 | If we all naturally had everything we could ever desire, the virtue of justice would be irrelevant [Hume] |
| 3918 | Moral philosophy aims to show us our duty [Hume] |
| 3919 | Conclusions of reason do not affect our emotions or decisions to act [Hume] |
| 3928 | Virtue just requires careful calculation and a preference for the greater happiness [Hume] |
| 3923 | No one would cause pain to a complete stranger who happened to be passing [Hume] |
| 3924 | Nature makes private affections come first, because public concerns are spread too thinly [Hume] |
| 3921 | The safety of the people is the supreme law [Hume] |
| 3927 | Society prefers helpful lies to harmful truth [Hume] |
| 3920 | If you equalise possessions, people's talents will make them unequal again [Hume] |