21 ideas
10282 | Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W] |
10283 | A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W] |
10284 | There are three different standard presentations of semantics [Hodges,W] |
10285 | I |= φ means that the formula φ is true in the interpretation I [Hodges,W] |
10288 | Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W] |
10289 | Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W] |
10287 | If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W] |
17867 | If a concept is not compact, it will not be presentable to finite minds [Almog] |
17877 | The number series is primitive, not the result of some set theoretic axioms [Almog] |
10286 | A 'set' is a mathematically well-behaved class [Hodges,W] |
17872 | Definitionalists rely on snapshot-concepts, instead of on the real processes [Almog] |
17871 | Fregean meanings are analogous to conceptual essence, defining a kind [Almog] |
17866 | Essential definition aims at existence conditions and structural truths [Almog] |
17868 | Surface accounts aren't exhaustive as they always allow unintended twin cases [Almog] |
17870 | Alien 'tigers' can't be tigers if they are not related to our tigers [Almog] |
17869 | Kripke and Putnam offer an intermediary between real and nominal essences [Almog] |
17876 | Individual essences are just cobbled together classificatory predicates [Almog] |
17873 | Water must be related to water, just as tigers must be related to tigers [Almog] |
19087 | The meaning or purport of a symbol is all the rational conduct it would lead to [Peirce] |
17864 | Defining an essence comes no where near giving a thing's nature [Almog] |
17863 | Essences promise to reveal reality, but actually drive us away from it [Almog] |