24 ideas
10928 | Maybe we can quantify modally if the objects are intensional, but it seems unlikely [Quine] |
13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton] |
13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton] |
13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton] |
13200 | Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton] |
13199 | The empty set may look pointless, but many sets can be constructed from it [Enderton] |
13203 | The singleton is defined using the pairing axiom (as {x,x}) [Enderton] |
13202 | Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton] |
13205 | We can only define functions if Choice tells us which items are involved [Enderton] |
10925 | Failure of substitutivity shows that a personal name is not purely referential [Quine] |
10926 | Quantifying into referentially opaque contexts often produces nonsense [Quine] |
10930 | Quantification into modal contexts requires objects to have an essence [Quine] |
14645 | To be necessarily greater than 7 is not a trait of 7, but depends on how 7 is referred to [Quine] |
9201 | Whether 9 is necessarily greater than 7 depends on how '9' is described [Quine, by Fine,K] |
10927 | Necessity only applies to objects if they are distinctively specified [Quine] |
9203 | We can't quantify in modal contexts, because the modality depends on descriptions, not objects [Quine, by Fine,K] |
7127 | If men are good you should keep promises, but they aren't, so you needn't [Machiavelli] |
6309 | The principle foundations of all states are good laws and good armies [Machiavelli] |
6306 | People are vengeful, so be generous to them, or destroy them [Machiavelli] |
6305 | To retain a conquered state, wipe out the ruling family, and preserve everything else [Machiavelli] |
6308 | A sensible conqueror does all his harmful deeds immediately, because people soon forget [Machiavelli] |
6307 | A desire to conquer, and men who do it, are always praised, or not blamed [Machiavelli] |
7486 | Machiavelli emancipated politics from religion [Machiavelli, by Watson] |
10931 | We can't say 'necessarily if x is in water then x dissolves' if we can't quantify modally [Quine] |