62 ideas
13310 | Wisdom does not lie in books, and unread people can also become wise [Seneca] |
13295 | Wise people escape necessity by willing it [Seneca] |
13317 | Philosophy aims at happiness [Seneca] |
13293 | What philosophy offers humanity is guidance [Seneca] |
13309 | That something is a necessary condition of something else doesn't mean it caused it [Seneca] |
13313 | Even philosophers have got bogged down in analysing tiny bits of language [Seneca] |
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] |
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] |
13297 | To the four causes Plato adds a fifth, the idea which guided the event [Seneca] |
13307 | If everything can be measured, try measuring the size of a man's soul [Seneca] |
21399 | Referring to a person, and speaking about him, are very different [Seneca] |
13325 | Trouble in life comes from copying other people, which is following convention instead of reason [Seneca] |
22239 | Humans acquired the concept of virtue from an analogy with bodily health and strength [Seneca, by Allen] |
13294 | We know death, which is like before birth; ceasing to be and never beginning are the same [Seneca] |
13299 | Living is nothing wonderful; what matters is to die well [Seneca] |
13300 | It is as silly to lament ceasing to be as to lament not having lived in the remote past [Seneca] |
13321 | Is anything sweeter than valuing yourself more when you find you are loved? [Seneca] |
13292 | Selfishness does not produce happiness; to live for yourself, live for others [Seneca] |
13303 | A man is as unhappy as he has convinced himself he is [Seneca] |
13302 | Life is like a play - it is the quality that matters, not the length [Seneca] |
13301 | We are scared of death - except when we are immersed in pleasure! [Seneca] |
13323 | The whole point of pleasure-seeking is novelty, and abandoning established ways [Seneca] |
13318 | Nature doesn't give us virtue; we must unremittingly pursue it, as a training and an art [Seneca] |
13324 | Living contrary to nature is like rowing against the stream [Seneca] |
13305 | Character is ruined by not looking back over our pasts, since the future rests on the past [Seneca] |
13308 | It's no good winning lots of fights, if you are then conquered by your own temper [Seneca] |
13312 | Excessive curiosity is a form of intemperance [Seneca] |
13315 | To govern used to mean to serve, not to rule; rulers did not test their powers over those who bestowed it [Seneca] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
13322 | Both teachers and pupils should aim at one thing - the improvement of the pupil [Seneca] |
13290 | One joy of learning is making teaching possible [Seneca] |
13298 | Suicide may be appropriate even when it is not urgent, if there are few reasons against it [Seneca] |
13319 | If we control our own death, no one has power over us [Seneca] |
13320 | Sometimes we have a duty not to commit suicide, for those we love [Seneca] |
13311 | Does time exist on its own? Did anything precede it? Did it pre-exist the cosmos? [Seneca] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |