40 ideas
| 11159 | My account shows how the concept works, rather than giving an analysis [Fine,K] |
| 11157 | Modern philosophy has largely abandoned real definitions, apart from sortals [Fine,K] |
| 11171 | Defining a term and giving the essence of an object don't just resemble - they are the same [Fine,K] |
| 7786 | Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle] |
| 7798 | There are three axiom schemas for propositional logic [Girle] |
| 7799 | Proposition logic has definitions for its three operators: or, and, and identical [Girle] |
| 7797 | Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle] |
| 7794 | There are seven modalities in S4, each with its negation [Girle] |
| 7793 | ◊p → □◊p is the hallmark of S5 [Girle] |
| 7795 | S5 has just six modalities, and all strings can be reduced to those [Girle] |
| 7787 | Possible worlds logics use true-in-a-world rather than true [Girle] |
| 7788 | Modal logic has four basic modal negation equivalences [Girle] |
| 7796 | Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle] |
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| 7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| 7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
| 11151 | An object is dependent if its essence prevents it from existing without some other object [Fine,K] |
| 11152 | Essences are either taken as real definitions, or as necessary properties [Fine,K] |
| 11161 | Essentially having a property is naturally expressed as 'the property it must have to be what it is' [Fine,K] |
| 11160 | Simple modal essentialism refers to necessary properties of an object [Fine,K] |
| 11158 | Essentialist claims can be formulated more clearly with quantified modal logic [Fine,K] |
| 11167 | Metaphysical necessity is a special case of essence, not vice versa [Fine,K] |
| 16537 | Essence as necessary properties produces a profusion of essential properties [Fine,K, by Lowe] |
| 11163 | The nature of singleton Socrates has him as a member, but not vice versa [Fine,K] |
| 11164 | It is not part of the essence of Socrates that a huge array of necessary truths should hold [Fine,K] |
| 10935 | An essential property of something must be bound up with what it is to be that thing [Fine,K, by Rami] |
| 10936 | Essential properties are part of an object's 'definition' [Fine,K, by Rami] |
| 11165 | If Socrates lacks necessary existence, then his nature cannot require his parents' existence [Fine,K] |
| 7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
| 7801 | Possibilities can be logical, theoretical, physical, economic or human [Girle] |
| 11166 | The subject of a proposition need not be the source of its necessity [Fine,K] |
| 11169 | Conceptual necessities rest on the nature of all concepts [Fine,K] |
| 11162 | Socrates is necessarily distinct from the Eiffel Tower, but that is not part of his essence [Fine,K] |
| 11168 | Metaphysical necessities are true in virtue of the nature of all objects [Fine,K] |
| 7792 | A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle] |
| 11170 | Analytic truth may only be true in virtue of the meanings of certain terms [Fine,K] |
| 11172 | The meaning of 'bachelor' is irrelevant to the meaning of 'unmarried man' [Fine,K] |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |