Combining Texts

All the ideas for 'The Logic of Boundaryless Concepts', 'First-Order Logic' and 'Conceptual truth and metaphysical necessity'

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18 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 / A. Overview of Logic / 3. Value of Logic
Logic guides thinking, but it isn't a substitute for it [Rumfitt]
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]
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 / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
The necessity of a proposition concerns reality, not our words or concepts [Stalnaker]
Conceptual possibilities are metaphysical possibilities we can conceive of [Stalnaker]
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
Critics say there are just an a priori necessary part, and an a posteriori contingent part [Stalnaker]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A 'centred' world is an ordered triple of world, individual and time [Stalnaker]
18. Thought / C. Content / 6. Broad Content
Meanings aren't in the head, but that is because they are abstract [Stalnaker]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
One view says the causal story is built into the description that is the name's content [Stalnaker]
19. Language / C. Assigning Meanings / 10. Two-Dimensional Semantics
Two-D says that a posteriori is primary and contingent, and the necessity is the secondary intension [Stalnaker]
In one view, the secondary intension is metasemantic, about how the thinker relates to the content [Stalnaker]