Combining Texts

All the ideas for 'Issues of Pragmaticism', 'First-Order Logic' and 'Nature Without Essence'

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21 ideas

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
There are three different standard presentations of semantics [Hodges,W]
I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
5. Theory of Logic / K. Features of Logics / 6. Compactness
If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W]
If a concept is not compact, it will not be presentable to finite minds [Almog]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / d. Natural numbers
The number series is primitive, not the result of some set theoretic axioms [Almog]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
A 'set' is a mathematically well-behaved class [Hodges,W]
9. Objects / D. Essence of Objects / 4. Essence as Definition
Definitionalists rely on snapshot-concepts, instead of on the real processes [Almog]
Fregean meanings are analogous to conceptual essence, defining a kind [Almog]
Essential definition aims at existence conditions and structural truths [Almog]
Surface accounts aren't exhaustive as they always allow unintended twin cases [Almog]
9. Objects / D. Essence of Objects / 10. Essence as Species
Alien 'tigers' can't be tigers if they are not related to our tigers [Almog]
9. Objects / D. Essence of Objects / 13. Nominal Essence
Kripke and Putnam offer an intermediary between real and nominal essences [Almog]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Individual essences are just cobbled together classificatory predicates [Almog]
18. Thought / C. Content / 5. Twin Earth
Water must be related to water, just as tigers must be related to tigers [Almog]
19. Language / A. Nature of Meaning / 1. Meaning
The meaning or purport of a symbol is all the rational conduct it would lead to [Peirce]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / e. Anti scientific essentialism
Defining an essence comes no where near giving a thing's nature [Almog]
Essences promise to reveal reality, but actually drive us away from it [Almog]