Combining Texts

All the ideas for 'Meno', 'The Union of Body and Soul' and 'Higher-Order Logic'

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25 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
1922 Spiritual qualities only become advantageous with the growth of wisdom [Plato]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
10301 The axiom of choice is controversial, but it could be replaced [Shapiro]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
10588 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
10298 Some say that second-order logic is mathematics, not logic [Shapiro]
10299 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
10300 Logical consequence can be defined in terms of the logical terminology [Shapiro]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
10290 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
10590 Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
10296 The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
10297 The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
10292 Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
5. Theory of Logic / L. Paradox / 2. Aporiai
11259 How can you seek knowledge of something if you don't know it? [Plato]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
10294 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
10591 Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
11. Knowledge Aims / A. Knowledge / 3. Value of Knowledge
20219 True opinions only become really valuable when they are tied down by reasons [Plato]
12. Knowledge Sources / A. A Priori Knowledge / 3. Innate Knowledge / b. Recollection doctrine
5985 Seeking and learning are just recollection [Plato]
5986 The slave boy learns geometry from questioning, not teaching, so it is recollection [Plato]
13. Knowledge Criteria / A. Justification Problems / 1. Justification / b. Need for justification
1923 As a guide to action, true opinion is as good as knowledge [Plato]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
1919 You don't need to learn what you know, and how do you seek for what you don't know? [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / d. Teaching virtue
1927 It seems that virtue is neither natural nor taught, but is a divine gift [Plato]
1913 Is virtue taught, or achieved by practice, or a natural aptitude, or what? [Plato]
1921 If virtue is a type of knowledge then it ought to be taught [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / j. Unity of virtue
1916 Even if virtues are many and various, they must have something in common to make them virtues [Plato]
1918 How can you know part of virtue without knowing the whole? [Plato]
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
2594 A true cause must involve a necessary connection between cause and effect [Malebranche]