8 ideas
15927 | Definition just needs negation, known variables, conjunction, disjunction, substitution and quantification [Weyl, by Lavine] |
16186 | The Barcan Formulas express how to combine modal operators with classical quantifiers [Simchen] |
16187 | The Barcan Formulas are orthodox, but clash with the attractive Actualist view [Simchen] |
16190 | BF implies that if W possibly had a child, then something is possibly W's child [Simchen] |
16188 | Serious Actualism says there are no facts at all about something which doesn't exist [Simchen] |
22745 | Pherecydes said the first principle and element is earth [Pherecydes, by Sext.Empiricus] |
10246 | The limit of science is isomorphism of theories, with essences a matter of indifference [Weyl] |
5883 | Pherecydes was the first to say that the soul is eternal [Pherecydes, by Cicero] |