19 ideas
14092 | Philosophers are often too fussy about words, dismissing perfectly useful ordinary terms [Rosen] |
14100 | Figuring in the definition of a thing doesn't make it a part of that thing [Rosen] |
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] |
14096 | Explanations fail to be monotonic [Rosen] |
10833 | Many concepts can only be expressed by second-order logic [Boolos] |
14097 | Things could be true 'in virtue of' others as relations between truths, or between truths and items [Rosen] |
14095 | Facts are structures of worldly items, rather like sentences, individuated by their ingredients [Rosen] |
14093 | An 'intrinsic' property is one that depends on a thing and its parts, and not on its relations [Rosen] |
14094 | The excellent notion of metaphysical 'necessity' cannot be defined [Rosen] |
14101 | Are necessary truths rooted in essences, or also in basic grounding laws? [Rosen] |
14099 | 'Bachelor' consists in or reduces to 'unmarried' male, but not the other way around [Rosen] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
14098 | An acid is just a proton donor [Rosen] |