42 ideas
| 7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
| 14239 | The empty set is usually derived from Separation, but it also seems to need Infinity [Oliver/Smiley] |
| 14240 | The empty set is something, not nothing! [Oliver/Smiley] |
| 14241 | We don't need the empty set to express non-existence, as there are other ways to do that [Oliver/Smiley] |
| 14242 | Maybe we can treat the empty set symbol as just meaning an empty term [Oliver/Smiley] |
| 14243 | The unit set may be needed to express intersections that leave a single member [Oliver/Smiley] |
| 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] |
| 14234 | If you only refer to objects one at a time, you need sets in order to refer to a plurality [Oliver/Smiley] |
| 14237 | We can use plural language to refer to the set theory domain, to avoid calling it a 'set' [Oliver/Smiley] |
| 14245 | Logical truths are true no matter what exists - but predicate calculus insists that something exists [Oliver/Smiley] |
| 14246 | If mathematics purely concerned mathematical objects, there would be no applied mathematics [Oliver/Smiley] |
| 14247 | Sets might either represent the numbers, or be the numbers, or replace the numbers [Oliver/Smiley] |
| 15127 | A categorical basis could hardly explain a disposition if it had no powers of its own [Hawthorne] |
| 15123 | Is the causal profile of a property its essence? [Hawthorne] |
| 15122 | Could two different properties have the same causal profile? [Hawthorne] |
| 15124 | If properties are more than their powers, we could have two properties with the same power [Hawthorne] |
| 14590 | If we accept scattered objects such as archipelagos, why not think of cars that way? [Hawthorne] |
| 15128 | We can treat the structure/form of the world differently from the nodes/matter of the world [Hawthorne] |
| 15121 | An individual essence is a necessary and sufficient profile for a thing [Hawthorne] |
| 14591 | Four-dimensionalists say instantaneous objects are more fundamental than long-lived ones [Hawthorne] |
| 8970 | Our notion of identical sets involves identical members, which needs absolute identity [Hawthorne] |
| 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] |
| 14589 | A modal can reverse meaning if the context is seen differently, so maybe context is all? [Hawthorne] |
| 7803 | Modal logic began with translation difficulties for 'If...then' [Lewis,CI, by Girle] |
| 19553 | Commitment to 'I have a hand' only makes sense in a context where it has been doubted [Hawthorne] |
| 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] |
| 19551 | How can we know the heavyweight implications of normal knowledge? Must we distort 'knowledge'? [Hawthorne] |
| 19552 | We wouldn't know the logical implications of our knowledge if small risks added up to big risks [Hawthorne] |
| 19554 | Denying closure is denying we know P when we know P and Q, which is absurd in simple cases [Hawthorne] |
| 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] |
| 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] |
| 15126 | Maybe scientific causation is just generalisation about the patterns [Hawthorne] |
| 15125 | We only know the mathematical laws, but not much else [Hawthorne] |
| 9363 | Science seeks classification which will discover laws, essences, and predictions [Lewis,CI] |
| 14588 | Modern metaphysicians tend to think space-time points are more fundamental than space-time regions [Hawthorne] |