47 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] |
| 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] |
| 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] |
| 17306 | If ground is transitive and irreflexive, it has a strict partial ordering, giving structure [Schaffer,J] |
| 17304 | As causation links across time, grounding links the world across levels [Schaffer,J] |
| 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] |
| 17308 | Explaining 'Adam ate the apple' depends on emphasis, and thus implies a contrast [Schaffer,J] |
| 6248 | Reason is too slow and doubtful to guide all actions, which need external and moral senses [Hutcheson] |
| 6238 | We approve of actions by a superior moral sense [Hutcheson] |
| 6239 | We dislike a traitor, even if they give us great benefit [Hutcheson] |
| 6240 | The moral sense is not an innate idea, but an ability to approve or disapprove in a disinterested way [Hutcheson] |
| 6242 | We cannot choose our moral feelings, otherwise bribery could affect them [Hutcheson] |
| 6247 | Everyone feels uneasy when seeing others in pain, unless the others are evil [Hutcheson] |
| 6244 | Human nature seems incapable of universal malice, except what results from self-love [Hutcheson] |
| 6243 | As death approaches, why do we still care about family, friends or country? [Hutcheson] |
| 6246 | My action is not made good by a good effect, if I did not foresee and intend it [Hutcheson] |
| 6241 | Contempt of danger is just madness if it is not in some worthy cause [Hutcheson] |
| 6245 | That action is best, which procures the greatest happiness for the greatest number [Hutcheson] |
| 6251 | The loss of perfect rights causes misery, but the loss of imperfect rights reduces social good [Hutcheson] |
| 17305 | I take what is fundamental to be the whole spatiotemporal manifold and its fields [Schaffer,J] |
| 17307 | Nowadays causation is usually understood in terms of equations and variable ranges [Schaffer,J] |
| 6250 | We say God is good if we think everything he does aims at the happiness of his creatures [Hutcheson] |
| 6249 | If goodness is constituted by God's will, it is a tautology to say God's will is good [Hutcheson] |