57 ideas
| 9108 | From an impossibility anything follows [William of Ockham] |
| 21616 | Truth and falsity apply to suppositions as well as to assertions [Williamson] |
| 21623 | True and false are not symmetrical; false is more complex, involving negation [Williamson] |
| 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] |
| 21602 | Many-valued logics don't solve vagueness; its presence at the meta-level is ignored [Williamson] |
| 21611 | Formal semantics defines validity as truth preserved in every model [Williamson] |
| 21606 | 'Bivalence' is the meta-linguistic principle that 'A' in the object language is true or false [Williamson] |
| 21605 | Excluded Middle is 'A or not A' in the object language [Williamson] |
| 9106 | The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham] |
| 21612 | Or-elimination is 'Argument by Cases'; it shows how to derive C from 'A or B' [Williamson] |
| 21599 | A sorites stops when it collides with an opposite sorites [Williamson] |
| 9113 | Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham] |
| 14664 | Necessary beings (numbers, properties, sets, propositions, states of affairs, God) exist in all possible worlds [Plantinga] |
| 9110 | The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham] |
| 21589 | When bivalence is rejected because of vagueness, we lose classical logic [Williamson] |
| 21596 | Vagueness undermines the stable references needed by logic [Williamson] |
| 21601 | A vague term can refer to very precise elements [Williamson] |
| 21629 | Equally fuzzy objects can be identical, so fuzziness doesn't entail vagueness [Williamson] |
| 21591 | Vagueness is epistemic. Statements are true or false, but we often don't know which [Williamson] |
| 21619 | If a heap has a real boundary, omniscient speakers would agree where it is [Williamson] |
| 21620 | The epistemic view says that the essence of vagueness is ignorance [Williamson] |
| 21622 | If there is a true borderline of which we are ignorant, this drives a wedge between meaning and use [Williamson] |
| 9120 | Vagueness in a concept is its indiscriminability from other possible concepts [Williamson] |
| 21625 | The vagueness of 'heap' can remain even when the context is fixed [Williamson] |
| 21614 | The 'nihilist' view of vagueness says that 'heap' is not a legitimate concept [Williamson] |
| 21617 | We can say propositions are bivalent, but vague utterances don't express a proposition [Williamson] |
| 21618 | If the vague 'TW is thin' says nothing, what does 'TW is thin if his perfect twin is thin' say? [Williamson] |
| 21590 | Asking when someone is 'clearly' old is higher-order vagueness [Williamson] |
| 21592 | Supervaluation keeps classical logic, but changes the truth in classical semantics [Williamson] |
| 21603 | You can't give a precise description of a language which is intrinsically vague [Williamson] |
| 21604 | Supervaluation assigns truth when all the facts are respected [Williamson] |
| 21607 | Supervaluation has excluded middle but not bivalence; 'A or not-A' is true, even when A is undecided [Williamson] |
| 21608 | Truth-functionality for compound statements fails in supervaluation [Williamson] |
| 21609 | Supervaluationism defines 'supertruth', but neglects it when defining 'valid' [Williamson] |
| 21610 | Supervaluation adds a 'definitely' operator to classical logic [Williamson] |
| 21613 | Supervaluationism cannot eliminate higher-order vagueness [Williamson] |
| 21633 | Nominalists suspect that properties etc are our projections, and could have been different [Williamson] |
| 15388 | Universals are single things, and only universal in what they signify [William of Ockham] |
| 21630 | If fuzzy edges are fine, then why not fuzzy temporal, modal or mereological boundaries? [Williamson] |
| 14666 | Socrates is a contingent being, but his essence is not; without Socrates, his essence is unexemplified [Plantinga] |
| 9109 | If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham] |
| 21632 | A river is not just event; it needs actual and counterfactual boundaries [Williamson] |
| 21621 | We can't infer metaphysical necessities to be a priori knowable - or indeed knowable in any way [Williamson] |
| 14662 | Possible worlds clarify possibility, propositions, properties, sets, counterfacts, time, determinism etc. [Plantinga] |
| 16472 | Plantinga's actualism is nominal, because he fills actuality with possibilia [Stalnaker on Plantinga] |
| 21627 | We have inexact knowledge when we include margins of error [Williamson] |
| 21626 | Knowing you know (KK) is usually denied if the knowledge concept is missing, or not considered [Williamson] |
| 21631 | To know, believe, hope or fear, one must grasp the thought, but not when you fail to do them [Williamson] |
| 21600 | 'Blue' is not a family resemblance, because all the blues resemble in some respect [Williamson] |
| 21615 | References to the 'greatest prime number' have no reference, but are meaningful [Williamson] |
| 18038 | The 't' and 'f' of formal semantics has no philosophical interest, and may not refer to true and false [Williamson] |
| 16469 | Plantinga has domains of sets of essences, variables denoting essences, and predicates as functions [Plantinga, by Stalnaker] |
| 16470 | Plantinga's essences have their own properties - so will have essences, giving a hierarchy [Stalnaker on Plantinga] |
| 14663 | Are propositions and states of affairs two separate things, or only one? I incline to say one [Plantinga] |
| 21624 | It is known that there is a cognitive loss in identifying propositions with possible worlds [Williamson] |
| 9105 | Some concepts for propositions exist only in the mind, and in no language [William of Ockham] |