5 ideas
15990 | Every individual thing which exists has an essence, which is its internal constitution [Locke] |
15994 | If it is knowledge, it is certain; if it isn't certain, it isn't knowledge [Locke] |
2614 | Modern phenomenalism holds that objects are logical constructions out of sense-data [Ayer] |
2615 | The concept of sense-data allows us to discuss appearances without worrying about reality [Ayer] |
9141 | Abstraction theories build mathematics out of second-order equivalence principles [Cook/Ebert] |