21 ideas
| 21406 | Because there is only one human reason, there can only be one true philosophy from principles [Kant] |
| 21548 | The null class is the class with all the non-existents as its members [MacColl, by Lackey] |
| 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] |
| 21081 | We are equipped with the a priori intuitions needed for the concept of right [Kant] |
| 21082 | A power-based state of nature may not be unjust, but there is no justice without competent judges [Kant] |
| 21089 | Monarchs have the highest power; autocrats have complete power [Kant] |
| 21086 | Hereditary nobility has not been earned, and probably won't be earned [Kant] |
| 21080 | Actions are right if the maxim respects universal mutual freedoms [Kant] |
| 21083 | Women have no role in politics [Kant] |
| 21407 | Equality is not being bound in ways you cannot bind others [Kant] |
| 21084 | In the contract people lose their rights, but immediately regain them, in the new commonwealth [Kant] |
| 21090 | If someone has largely made something, then they own it [Kant] |
| 21087 | Human life is pointless without justice [Kant] |
| 21088 | Justice asserts the death penalty for murder, from a priori laws [Kant] |
| 21085 | The church has a political role, by offering a supreme power over people [Kant] |