31 ideas
19695 | The devil was wise as an angel, and lost no knowledge when he rebelled [Whitcomb] |
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] |
5735 | Maybe names and predicates can capture any fact [Melia] |
5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
12132 | Indiscernibility is a necessary and sufficient condition for identity [Brody] |
15834 | Brody bases sortal essentialism on properties required throughout something's existence [Brody, by Mackie,P] |
12140 | Modern emphasis is on properties had essentially; traditional emphasis is on sort-defining properties [Brody] |
11895 | A sortal essence is a property which once possessed always possessed [Brody, by Mackie,P] |
12141 | Maybe essential properties are those which determine a natural kind? [Brody] |
12137 | De re essentialism standardly says all possible objects identical with a have a's essential properties [Brody] |
12142 | Essentially, a has P, always had P, must have had P, and has never had a future without P [Brody] |
12143 | An object having a property essentially is equivalent to its having it necessarily [Brody] |
12144 | Essentialism is justified if the essential properties of things explain their other properties [Brody] |
12139 | Mereological essentialism says that every part that ensures the existence is essential [Brody] |
12135 | Interrupted objects have two first moments of existence, which could be two beginnings [Brody] |
5746 | The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia] |
12130 | a and b share all properties; so they share being-identical-with-a; so a = b [Brody] |
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] |
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] |
5751 | The truth of propositions at possible worlds are implied by the world, just as in books [Melia] |
12138 | Identity across possible worlds is prior to rigid designation [Brody] |
5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |