28 ideas
| 18806 | Frege thought traditional categories had psychological and linguistic impurities [Frege, by Rumfitt] |
| 8490 | First-level functions have objects as arguments; second-level functions take functions as arguments [Frege] |
| 8492 | Relations are functions with two arguments [Frege] |
| 8487 | Arithmetic is a development of logic, so arithmetical symbolism must expand into logical symbolism [Frege] |
| 18899 | Frege takes the existence of horses to be part of their concept [Frege, by Sommers] |
| 4028 | Frege allows either too few properties (as extensions) or too many (as predicates) [Mellor/Oliver on Frege] |
| 8489 | The concept 'object' is too simple for analysis; unlike a function, it is an expression with no empty place [Frege] |
| 9947 | Concepts are the ontological counterparts of predicative expressions [Frege, by George/Velleman] |
| 10319 | An assertion about the concept 'horse' must indirectly speak of an object [Frege, by Hale] |
| 8488 | A concept is a function whose value is always a truth-value [Frege] |
| 9948 | Unlike objects, concepts are inherently incomplete [Frege, by George/Velleman] |
| 4972 | I may regard a thought about Phosphorus as true, and the same thought about Hesperus as false [Frege] |
| 21059 | General rules of action also need a judgement about when to apply them [Kant] |
| 21061 | Duty does not aim at an end, but gives rise to universal happiness as aim of the will [Kant] |
| 21060 | It can't be a duty to strive after the impossible [Kant] |
| 21062 | The will's motive is the absolute law itself, and moral feeling is receptivity to law [Kant] |
| 21071 | There can be no restraints on freedom if reason does not reveal some basic rights [Kant] |
| 21063 | Personal contracts are for some end, but a civil state contract involves a duty to share [Kant] |
| 21068 | There must be a unanimous contract that citizens accept majority decisions [Kant] |
| 21069 | A contract is theoretical, but it can guide rulers to make laws which the whole people will accept [Kant] |
| 21070 | A law is unjust if the whole people could not possibly agree to it [Kant] |
| 21067 | A citizen must control his own life, and possess property or an important skill [Kant] |
| 21064 | A lawful civil state must embody freedom, equality and independence for its members [Kant] |
| 21066 | Citizens can rise to any rank that talent, effort and luck can achieve [Kant] |
| 21065 | You can't make a contract renouncing your right to make contracts! [Kant] |
| 21072 | The people (who have to fight) and not the head of state should declare a war [Kant] |
| 2116 | The concept of an existing thing must contain more than the concept of a non-existing thing [Leibniz] |
| 8491 | The Ontological Argument fallaciously treats existence as a first-level concept [Frege] |