41 ideas
| 15169 | Metaphysics is clarifying how we speak and think (and possibly improving it) [Sidelle] |
| 15164 | We seem to base necessities on thought experiments and imagination [Sidelle] |
| 10888 | Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo] |
| 10889 | The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo] |
| 10890 | A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo] |
| 10886 | Determinacy: an object is either in a set, or it isn't [Zalabardo] |
| 10887 | Specification: Determinate totals of objects always make a set [Zalabardo] |
| 10897 | A first-order 'sentence' is a formula with no free variables [Zalabardo] |
| 10893 | Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo] |
| 10899 | Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo] |
| 10896 | Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo] |
| 10898 | The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo] |
| 10902 | We can do semantics by looking at given propositions, or by building new ones [Zalabardo] |
| 10892 | We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo] |
| 10895 | 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo] |
| 10900 | Logically true sentences are true in all structures [Zalabardo] |
| 10901 | Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo] |
| 10894 | A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo] |
| 10903 | A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo] |
| 10891 | If a set is defined by induction, then proof by induction can be applied to it [Zalabardo] |
| 15180 | There doesn't seem to be anything in the actual world that can determine modal facts [Sidelle] |
| 15184 | Causal reference presupposes essentialism if it refers to modally extended entities [Sidelle] |
| 15172 | Clearly, essential predications express necessary properties [Sidelle] |
| 15181 | Being a deepest explanatory feature is an actual, not a modal property [Sidelle] |
| 15173 | That the essence of water is its microstructure is a convention, not a discovery [Sidelle] |
| 15185 | We aren't clear about 'same stuff as this', so a principle of individuation is needed to identify it [Sidelle] |
| 15175 | Evaluation of de dicto modalities does not depend on the identity of its objects [Sidelle] |
| 15032 | Necessary a posteriori is conventional for necessity and nonmodal for a posteriority [Sidelle, by Sider] |
| 15179 | To know empirical necessities, we need empirical facts, plus conventions about which are necessary [Sidelle] |
| 15171 | The necessary a posteriori is statements either of identity or of essence [Sidelle] |
| 15167 | Empiricism explores necessities and concept-limits by imagining negations of truths [Sidelle] |
| 15177 | Contradictoriness limits what is possible and what is imaginable [Sidelle] |
| 15176 | The individuals and kinds involved in modality are also a matter of convention [Sidelle] |
| 15174 | A thing doesn't need transworld identity prior to rigid reference - that could be a convention of the reference [Sidelle] |
| 15183 | 'Dthat' operates to make a singular term into a rigid term [Sidelle] |
| 15165 | A priori knowledge is entirely of analytic truths [Sidelle] |
| 604 | Knowledge is mind and knowing 'cohabiting' [Lycophron, by Aristotle] |
| 15168 | That water is essentially H2O in some way concerns how we use 'water' [Sidelle] |
| 15166 | Causal reference seems to get directly at the object, thus leaving its nature open [Sidelle] |
| 15182 | Because some entities overlap, reference must have analytic individuation principles [Sidelle] |
| 15178 | Can anything in science reveal the necessity of what it discovers? [Sidelle] |