33 ideas
| 7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
| 9358 | There are several logics, none of which will ever derive falsehoods from truth [Lewis,CI] |
| 9357 | Excluded middle is just our preference for a simplified dichotomy in experience [Lewis,CI] |
| 9364 | Names represent a uniformity in experience, or they name nothing [Lewis,CI] |
| 11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
| 9362 | Necessary truths are those we will maintain no matter what [Lewis,CI] |
| 7803 | Modal logic began with translation difficulties for 'If...then' [Lewis,CI, by Girle] |
| 9365 | We can maintain a priori principles come what may, but we can also change them [Lewis,CI] |
| 21500 | We rely on memory for empirical beliefs because they mutually support one another [Lewis,CI] |
| 21501 | If we doubt memories we cannot assess our doubt, or what is being doubted [Lewis,CI] |
| 6556 | If anything is to be probable, then something must be certain [Lewis,CI] |
| 21498 | Congruents assertions increase the probability of each individual assertion in the set [Lewis,CI] |
| 6027 | From the fact that some men die, we cannot infer that they all do [Philodemus] |
| 5828 | Extension is the class of things, intension is the correct definition of the thing, and intension determines extension [Lewis,CI] |
| 9361 | We have to separate the mathematical from physical phenomena by abstraction [Lewis,CI] |
| 20289 | Ethics is universalisable - it must involve an impartial and universal view of things [Singer] |
| 20286 | Following an inner voice for morality is irresponsible in a rational agent [Singer] |
| 20282 | The sanctity of a human life depends either on being of our species, or on being a person [Singer] |
| 20278 | 'Marginal utility' says something is more useful if it is in short supply [Singer] |
| 20281 | Why should I do anything for posterity? What has posterity ever done for me? [Singer] |
| 22241 | Don't fear god or worry about death; the good is easily got and the terrible easily cured [Philodemus] |
| 20276 | Conflict of rules might be avoided by greater complexity, or by a hierarchy of rules [Singer] |
| 20290 | Psychopaths may just be bored, because they cannot participate in normal emotional life [Singer] |
| 20288 | You can't condemn violent revolution without assessing the evils it prevents [Singer] |
| 21997 | In Marxism the state will be superseded [Singer] |
| 20287 | If 49% of the population can be wrong, so can 51% [Singer] |
| 21993 | Materialist history says we are subject to incomprehensible forces [Singer] |
| 20277 | Equality of interests is a minimal principle, not implying equal treatment [Singer] |
| 20279 | Equality of opportunity unfairly rewards those lucky enough to have great ability [Singer] |
| 20285 | If a right entails having the relevant desire, many creatures might have no right to life [Singer] |
| 20284 | Why should a potential person have the rights of an actual person? [Singer] |
| 20283 | Killing a chimp is worse than killing a human too defective to be a person [Singer] |
| 9363 | Science seeks classification which will discover laws, essences, and predictions [Lewis,CI] |