14 ideas
| 14249 | Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley] |
| 10830 | Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos] |
| 10829 | A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos] |
| 10832 | '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos] |
| 10834 | Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos] |
| 13841 | Why should compactness be definitive of logic? [Boolos, by Hacking] |
| 10833 | Many concepts can only be expressed by second-order logic [Boolos] |
| 16641 | Whiteness does not exist, but by it something can exist-as-white [Aquinas] |
| 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] |
| 21785 | We are only free, with rights, if we claim our freedom, and there are no natural rights [Hegel, by Houlgate] |
| 22041 | Representatives by region ignores whether they care about the national interest [Hegel, by Pinkard] |
| 21781 | The absolute right is the right to have rights [Hegel] |