42 ideas
19342 | Reason avoids multiplying hypotheses or principles [Leibniz] |
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] |
12711 | The immediate cause of movements is more real [than geometry] [Leibniz] |
19349 | The complete notion of a substance implies all of its predicates or attributes [Leibniz] |
7558 | Substances mirror God or the universe, each from its own viewpoint [Leibniz] |
16761 | Forms are of no value in physics, but are indispensable in metaphysics [Leibniz] |
13088 | Subjects include predicates, so full understanding of subjects reveals all the predicates [Leibniz] |
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] |
13085 | Leibniz is some form of haecceitist [Leibniz, by Cover/O'Leary-Hawthorne] |
5024 | Knowledge doesn't just come from the senses; we know the self, substance, identity, being etc. [Leibniz] |
5027 | If a person's memories became totally those of the King of China, he would be the King of China [Leibniz] |
5023 | Future contingent events are certain, because God foresees them, but that doesn't make them necessary [Leibniz] |
2119 | People argue for God's free will, but it isn't needed if God acts in perfection following supreme reason [Leibniz] |
5025 | Mind and body can't influence one another, but God wouldn't intervene in the daily routine [Leibniz] |
23996 | Akrasia is intelligible in hindsight, when we revisit our previous emotions [Blackburn] |
5026 | Animals lack morality because they lack self-reflection [Leibniz] |