8 ideas
19389 | Truth is a characteristic of possible thoughts [Leibniz] |
19388 | True and false seem to pertain to thoughts, yet unthought propositions seem to be true or false [Leibniz] |
9565 | Zermelo made 'set' and 'member' undefined axioms [Zermelo, by Chihara] |
3339 | For Zermelo's set theory the empty set is zero and the successor of each number is its unit set [Zermelo, by Blackburn] |
10196 | The Axiom of Choice needs a criterion of choice [Black] |
10194 | Two things can only be distinguished by a distinct property or a distinct relation [Black] |
10193 | The 'property' of self-identity is uselessly tautological [Black] |
10195 | If the universe just held two indiscernibles spheres, that refutes the Identity of Indiscernibles [Black] |