66 ideas
21474 | Metaphysics studies the inexplicable ends of explanation [Schopenhauer] |
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] |
11115 | 'All horses' either picks out the horses, or the things which are horses [Jubien] |
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] |
21470 | For me the objective thing-in-itself is the will [Schopenhauer] |
11116 | Being a physical object is our most fundamental category [Jubien] |
11117 | Haecceities implausibly have no qualities [Jubien] |
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] |
11119 | De re necessity is just de dicto necessity about object-essences [Jubien] |
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] |
11118 | Modal propositions transcend the concrete, but not the actual [Jubien] |
11108 | Your properties, not some other world, decide your possibilities [Jubien] |
11111 | Modal truths are facts about parts of this world, not about remote maximal entities [Jubien] |
11105 | We have no idea how many 'possible worlds' there might be [Jubien] |
11109 | If other worlds exist, then they are scattered parts of the actual world [Jubien] |
11106 | If all possible worlds just happened to include stars, their existence would be necessary [Jubien] |
11107 | If there are no other possible worlds, do we then exist necessarily? [Jubien] |
11112 | Possible worlds just give parallel contingencies, with no explanation at all of necessity [Jubien] |
11113 | Worlds don't explain necessity; we use necessity to decide on possible worlds [Jubien] |
11110 | We mustn't confuse a similar person with the same person [Jubien] |
21479 | Knowledge is not power! Ignorant people possess supreme authority [Schopenhauer] |
21476 | A priori propositions are those we could never be seriously motivated to challenge [Schopenhauer] |
21473 | All knowledge and explanation rests on the inexplicable [Schopenhauer] |
21478 | Half our thinking is unconscious, and we reach conclusions while unaware of premises [Schopenhauer] |
21477 | We don't control our own thinking [Schopenhauer] |
21475 | All of our concepts are borrowed from perceptual knowledge [Schopenhauer] |
21372 | Aesthetics concerns how we can take pleasure in an object, with no reference to the will [Schopenhauer] |
21488 | The beautiful is a perception of Plato's Forms, which eliminates the will [Schopenhauer] |
21483 | Man is essentially a dreadful wild animal [Schopenhauer] |
21466 | Pleasure is weaker, and pain stronger, than we expect [Schopenhauer] |
21484 | A man's character can be learned from a single characteristic action [Schopenhauer] |
21481 | Buddhists wisely start with the cardinal vices [Schopenhauer] |
21482 | The five Chinese virtues: pity, justice, politeness, wisdom, honesty [Schopenhauer] |
21469 | Human life is a mistake, shown by boredom, which is direct awareness of the fact [Schopenhauer] |
21480 | Boredom is only felt by those clever enough to need activity [Schopenhauer] |
21485 | The state only exists to defend citizens, from exterior threats, and from one another [Schopenhauer] |
21486 | Poverty and slavery are virtually two words for the same thing [Schopenhauer] |
21487 | The freedom of the press to sell poison outweighs its usefulness [Schopenhauer] |
21471 | If suicide was quick and easy, most people would have done it by now [Schopenhauer] |
21467 | Would humanity still exist if sex wasn't both desired and pleasurable? [Schopenhauer] |
21472 | Only religion introduces serious issues to uneducated people [Schopenhauer] |
21468 | The Creator created the possibilities for worlds, so should have made a better one than this possible [Schopenhauer] |