15 ideas
| 9108 | From an impossibility anything follows [William of Ockham] |
| 9107 | A proposition is true if its subject and predicate stand for the same thing [William of Ockham] |
| 16300 | Ockham had an early axiomatic account of truth [William of Ockham, by Halbach] |
| 19053 | Logic would be more natural if negation only referred to predicates [Dummett] |
| 10196 | The Axiom of Choice needs a criterion of choice [Black] |
| 19052 | Natural language 'not' doesn't apply to sentences [Dummett] |
| 9106 | The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham] |
| 9113 | Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham] |
| 9110 | The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham] |
| 15388 | Universals are single things, and only universal in what they signify [William of Ockham] |
| 10194 | Two things can only be distinguished by a distinct property or a distinct relation [Black] |
| 9109 | If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham] |
| 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] |
| 9105 | Some concepts for propositions exist only in the mind, and in no language [William of Ockham] |