50 ideas
6319 | Wise people choose inaction and silence [Laozi (Lao Tzu)] |
6325 | One who knows does not speak; one who speaks does not know [Laozi (Lao Tzu)] |
6321 | Vulgar people are alert; I alone am muddled [Laozi (Lao Tzu)] |
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] |
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] |
10185 | Set theory is the standard background for modern mathematics [Burgess] |
10184 | Structuralists take the name 'R' of the reals to be a variable ranging over structures, not a structure [Burgess] |
10189 | There is no one relation for the real number 2, as relations differ in different models [Burgess] |
10186 | If set theory is used to define 'structure', we can't define set theory structurally [Burgess] |
10187 | Abstract algebra concerns relations between models, not common features of all the models [Burgess] |
10188 | How can mathematical relations be either internal, or external, or intrinsic? [Burgess] |
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] |
6328 | To know yet to think that one does not know is best [Laozi (Lao Tzu)] |
6323 | Pursuit of learning increases activity; the Way decreases it [Laozi (Lao Tzu)] |
2975 | That honey is sweet I do not affirm, but I agree that it appears so [Timon] |
6331 | Truth is not beautiful; beautiful speech is not truthful [Laozi (Lao Tzu)] |
6330 | One with no use for life is wiser than one who values it [Laozi (Lao Tzu)] |
6327 | Do good to him who has done you an injury [Laozi (Lao Tzu)] |
23402 | The highest virtue is achieved without effort [Laozi (Lao Tzu)] |
6324 | To gain in goodness, treat as good those who are good, and those who are not [Laozi (Lao Tzu)] |
6322 | There is no crime greater than having too many desires [Laozi (Lao Tzu)] |
6320 | The best rulers are invisible, the next admired, the next feared, and the worst are exploited [Laozi (Lao Tzu)] |
6329 | People are hard to govern because authorities love to do things [Laozi (Lao Tzu)] |
6326 | The better known the law, the more criminals there are [Laozi (Lao Tzu)] |
23401 | A military victory is not a thing of beauty [Laozi (Lao Tzu)] |