12 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] |
5044 | Reality must be made of basic unities, which will be animated, substantial points [Leibniz] |
5045 | No machine or mere organised matter could have a unified self [Leibniz] |
5046 | The soul does know bodies, although they do not influence one another [Leibniz] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
5043 | To regard animals as mere machines may be possible, but seems improbable [Leibniz] |