33 ideas
5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
5737 | Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia] |
5744 | First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia] |
5740 | Second-order logic needs second-order variables and quantification into predicate position [Melia] |
5741 | If every model that makes premises true also makes conclusion true, the argument is valid [Melia] |
5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
5735 | Maybe names and predicates can capture any fact [Melia] |
17000 | We might fix identities for small particulars, but it is utopian to hope for such things [Kripke] |
14082 | No sortal could ever exactly pin down which set of particles count as this 'cup' [Schaffer,J] |
11868 | A different piece of wood could have been used for that table; constitution isn't identity [Wiggins on Kripke] |
17044 | A relation can clearly be reflexive, and identity is the smallest reflexive relation [Kripke] |
14081 | Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J] |
5746 | The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia] |
16999 | A vague identity may seem intransitive, and we might want to talk of 'counterparts' [Kripke] |
5738 | We may be sure that P is necessary, but is it necessarily necessary? [Melia] |
5732 | 'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia] |
17058 | What many people consider merely physically necessary I consider completely necessary [Kripke] |
4970 | What is often held to be mere physical necessity is actually metaphysical necessity [Kripke] |
17059 | Unicorns are vague, so no actual or possible creature could count as a unicorn [Kripke] |
5739 | Sometimes we want to specify in what ways a thing is possible [Melia] |
5734 | Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia] |
5742 | In possible worlds semantics the modal operators are treated as quantifiers [Melia] |
5743 | If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia] |
5749 | Possible worlds could be real as mathematics, propositions, properties, or like books [Melia] |
4950 | Possible worlds are useful in set theory, but can be very misleading elsewhere [Kripke] |
5751 | The truth of propositions at possible worlds are implied by the world, just as in books [Melia] |
17003 | Kaplan's 'Dthat' is a useful operator for transforming a description into a rigid designation [Kripke] |
9221 | The best known objection to counterparts is Kripke's, that Humphrey doesn't care if his counterpart wins [Kripke, by Sider] |
17052 | The a priori analytic truths involving fixing of reference are contingent [Kripke] |
4969 | I regard the mind-body problem as wide open, and extremely confusing [Kripke] |
5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
4956 | A description may fix a reference even when it is not true of its object [Kripke] |
17032 | Even if Gödel didn't produce his theorems, he's still called 'Gödel' [Kripke] |