22 ideas
| 23825 | We seek truth only because it is good [Weil] |
| 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] |
| 14979 | Being alone doesn't guarantee intrinsic properties; 'being alone' is itself extrinsic [Lewis, by Sider] |
| 15454 | Extrinsic properties come in degrees, with 'brother' less extrinsic than 'sibling' [Lewis] |
| 15455 | Total intrinsic properties give us what a thing is [Lewis] |
| 23826 | Beauty, goodness and truth are only achieved by applying full attention [Weil] |
| 23833 | The good is a nothingness, and yet real [Weil] |
| 23808 | There are two goods - the absolute good we want, and the reachable opposite of evil [Weil] |
| 23831 | The essence of power is illusory prestige [Weil] |
| 23830 | A group is only dangerous if it endorses an abstract entity [Weil] |
| 23809 | Our only social duty is to try to limit evil [Weil] |
| 23807 | The collective is the one and only object of false idolatry [Weil] |
| 23810 | Charity is the only love, and you can feel that for a country (a place with traditions), but not a nation [Weil] |
| 23811 | If effort is from necessity rather than for a good, it is slavery [Weil] |
| 23765 | The soul is the intrinsic value of a human [Weil] |