12 ideas
14970 | Normal system K has five axioms and rules [Cresswell] |
14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
16641 | Whiteness does not exist, but by it something can exist-as-white [Aquinas] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
22170 | Senses grasp external properties, but the understanding grasps the essential natures of things [Aquinas] |
22169 | Initial universal truths are present within us as potential, to be drawn out by reason [Aquinas] |
22168 | Minds take in a likeness of things, which activates an awaiting potential [Aquinas] |