23 ideas
10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
10478 | Since first-order languages are complete, |= and |- have the same meaning [Hodges,W] |
10477 | |= in model-theory means 'logical consequence' - it holds in all models [Hodges,W] |
10474 | |= should be read as 'is a model for' or 'satisfies' [Hodges,W] |
10473 | Model theory studies formal or natural language-interpretation using set-theory [Hodges,W] |
10475 | A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W] |
10481 | Models in model theory are structures, not sets of descriptions [Hodges,W] |
10480 | First-order logic can't discriminate between one infinite cardinal and another [Hodges,W] |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
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] |