15 ideas
| 7662 | Romanticism is the greatest change in the consciousness of the West [Berlin] |
| 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] |
| 13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
| 7665 | Most Enlightenment thinkers believed that virtue consists ultimately in knowledge [Berlin] |
| 7676 | If we are essentially free wills, authenticity and sincerity are the highest virtues [Berlin] |
| 7664 | The Greeks have no notion of obligation or duty [Berlin] |
| 7677 | Central to existentialism is the romantic idea that there is nothing to lean on [Berlin] |
| 7663 | Judaism and Christianity views are based on paternal, family and tribal relations [Berlin] |