Combining Philosophers

All the ideas for Anon (Diss), Wilfrid Hodges and Gregory Vlastos

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26 ideas

2. Reason / D. Definition / 7. Contextual Definition
The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
True and false statements can use exactly the same words [Anon (Diss)]
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 / 5. First-Order Logic
Since first-order languages are complete, |= and |- have the same meaning [Hodges,W]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
|= in model-theory means 'logical consequence' - it holds in all models [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 / I. Semantics of Logic / 4. Satisfaction
|= should be read as 'is a model for' or 'satisfies' [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W]
Model theory studies formal or natural language-interpretation using set-theory [Hodges,W]
Models in model theory are structures, not sets of descriptions [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [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 / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
First-order logic can't discriminate between one infinite cardinal and another [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]
13. Knowledge Criteria / E. Relativism / 4. Cultural relativism
Anything can be acceptable in some circumstances and unacceptable in others [Anon (Diss)]
Thracians think tattooing adds to a girl's beauty, but elsewhere it is a punishment [Anon (Diss)]
Lydians prostitute their daughters to raise a dowery, but no Greek would marry such a girl [Anon (Diss)]
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
How could someone who knows everything fail to act correctly? [Anon (Diss)]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
Every apparent crime can be right in certain circumstances [Anon (Diss), by PG]
22. Metaethics / C. The Good / 1. Goodness / g. Consequentialism
It is right to lie to someone, to get them to take medicine they are reluctant to take [Anon (Diss)]
24. Political Theory / D. Ideologies / 5. Democracy / b. Consultation
The first priority in elections is to vote for people who support democracy [Anon (Diss)]
25. Social Practice / D. Justice / 3. Punishment / b. Retribution for crime
In early Greece the word for punishment was also the word for vengeance [Vlastos]
25. Social Practice / E. Policies / 5. Education / c. Teaching
We learn language, and we don't know who teaches us it [Anon (Diss)]