20 ideas
| 20320 | Truth is what unites, and the profound truths create a community [Jaspers] |
| 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] |
| 20323 | Freedom needs knowledge, the possibility of arbitrariness, and law [Jaspers] |
| 20322 | I am aware that freedom is possible, and the freedom is not in theory, but in seeking freedom [Jaspers] |
| 20324 | My freedom increases as I broaden my vision of possiblities and motives [Jaspers] |
| 20321 | The struggle for Existenz is between people who are equals, and are utterly honest [Jaspers] |
| 20318 | My helplessness in philosophising reveals my being, and begins its upsurge [Jaspers] |
| 20325 | Once we grasp freedom 'from' things, then freedom 'for' things becomes urgent [Jaspers] |
| 20315 | 'Existenz' is the potential being, which I could have, and ought to have [Jaspers] |
| 20317 | Mundane existence is general, falling under universals, but Existens is unique to individuals [Jaspers] |
| 20319 | We want the correct grasp on being that is neither solipsism nor absorption in the crowd [Jaspers] |
| 20316 | Every decision I make moves towards or away from fulfilled Existenz [Jaspers] |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |