Combining Texts

All the ideas for 'Theory of Knowledge (2nd edn)', 'fragments/reports' and 'Higher-Order Logic'

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24 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
Most philosophers start with reality and then examine knowledge; Descartes put the study of knowledge first [Lehrer]
1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Carneades' pinnacles of philosophy are the basis of knowledge (the criterion of truth) and the end of appetite (good) [Carneades, by Cicero]
1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
You cannot demand an analysis of a concept without knowing the purpose of the analysis [Lehrer]
3. Truth / B. Truthmakers / 10. Making Future Truths
Future events are true if one day we will say 'this event is happening now' [Carneades]
We say future things are true that will possess actuality at some following time [Carneades, by Cicero]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice is controversial, but it could be replaced [Shapiro]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Some say that second-order logic is mathematics, not logic [Shapiro]
If the aim of logic is to codify inferences, second-order logic is useless [Shapiro]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Logical consequence can be defined in terms of the logical terminology [Shapiro]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order variables also range over properties, sets, relations or functions [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro]
8. Modes of Existence / B. Properties / 11. Properties as Sets
Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
9. Objects / F. Identity among Objects / 6. Identity between Objects
Carneades denied the transitivity of identity [Carneades, by Chisholm]
10. Modality / A. Necessity / 3. Types of Necessity
Carneades distinguished logical from causal necessity, when talking of future events [Long on Carneades]
16. Persons / F. Free Will / 2. Sources of Free Will
Voluntary motion is intrinsically within our power, and this power is its cause [Carneades, by Cicero]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
Some actions are within our power; determinism needs prior causes for everything - so it is false [Carneades, by Cicero]
16. Persons / F. Free Will / 6. Determinism / b. Fate
Even Apollo can only foretell the future when it is naturally necessary [Carneades, by Cicero]
22. Metaethics / B. Value / 2. Values / i. Self-interest
Carneades said that after a shipwreck a wise man would seize the only plank by force [Carneades, by Tuck]
25. Social Practice / D. Justice / 1. Basis of justice
People change laws for advantage; either there is no justice, or it is a form of self-injury [Carneades, by Lactantius]