20 ideas
14519 | It is a great good to show reverence for a wise man [Epicurus] |
14518 | In the study of philosophy, pleasure and knowledge arrive simultaneously [Epicurus] |
23367 | Even pointing a finger should only be done for a reason [Epictetus] |
10282 | Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W] |
10283 | A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W] |
10284 | There are three different standard presentations of semantics [Hodges,W] |
10285 | I |= φ means that the formula φ is true in the interpretation I [Hodges,W] |
10288 | Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W] |
10289 | Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W] |
10287 | If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W] |
10286 | A 'set' is a mathematically well-behaved class [Hodges,W] |
14524 | Bodies are combinations of shape, size, resistance and weight [Epicurus] |
14521 | If everything is by necessity, then even denials of necessity are by necessity [Epicurus] |
14522 | What happens to me if I obtain all my desires, and what if I fail? [Epicurus] |
3563 | Pleasure and virtue entail one another [Epicurus] |
3560 | Justice is merely a contract about not harming or being harmed [Epicurus] |
14517 | We value our own character, whatever it is, and we should respect the characters of others [Epicurus] |
14513 | Justice is a pledge of mutual protection [Epicurus] |
14515 | A law is not just if it is not useful in mutual associations [Epicurus] |
14520 | It is small-minded to find many good reasons for suicide [Epicurus] |