Combining Philosophers

All the ideas for Tom Clark, Jos L. Zalabardo and Hugh LaFollette

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25 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo]
A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Determinacy: an object is either in a set, or it isn't [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / l. Axiom of Specification
Specification: Determinate totals of objects always make a set [Zalabardo]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
A first-order 'sentence' is a formula with no free variables [Zalabardo]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo]
Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo]
We can do semantics by looking at given propositions, or by building new ones [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 2. Formal Truth
We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
'Logically true' (|= φ) is true for every truth-assignment [Zalabardo]
Logically true sentences are true in all structures [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo]
A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
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]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
If a set is defined by induction, then proof by induction can be applied to it [Zalabardo]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / d. Purpose of consciousness
A very powerful computer might have its operations restricted by the addition of consciousness [Clark,T]
20. Action / C. Motives for Action / 5. Action Dilemmas / a. Dilemmas
We can discuss the criteria of a judgment, or the weight given to them, or their application [LaFollette]
Errors in moral practice might be inconsistent or inappropriate principles, or inappropriate application [LaFollette]
20. Action / C. Motives for Action / 5. Action Dilemmas / c. Omissions
The act/omission distinction is important for duties, but less so for consequences [LaFollette]
23. Ethics / D. Deontological Ethics / 2. Duty
Are we only obligated by agreement, or should we always help the weak? [LaFollette]
25. Social Practice / C. Rights / 2. Moral rights
Too many options may open us to unwanted pressures, like being paid very little [LaFollette]
Should people be forced to make choices? [LaFollette]