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All the ideas for 'The Philosophy of Philosophy', 'Virtues and Vices' and 'Understanding the Infinite'

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54 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
We take courage, temperance, wisdom and justice as moral, but Aristotle takes wisdom as intellectual [Foot]
1. Philosophy / A. Wisdom / 2. Wise People
Wisdom is open to all, and not just to the clever or well trained [Foot]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Progress in philosophy is incremental, not an immature seeking after drama [Williamson]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
Correspondence to the facts is a bad account of analytic truth [Williamson]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Second-order set theory just adds a version of Replacement that quantifies over functions [Lavine]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one [Lavine]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / a. Types of set
Collections of things can't be too big, but collections by a rule seem unlimited in size [Lavine]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / d. Infinite Sets
Those who reject infinite collections also want to reject the Axiom of Choice [Lavine]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / g. Axiom of Powers VI
The Power Set is just the collection of functions from one collection to another [Lavine]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII
Replacement was immediately accepted, despite having very few implications [Lavine]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets [Lavine]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Pure collections of things obey Choice, but collections defined by a rule may not [Lavine]
The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / c. Logical sets
The 'logical' notion of class has some kind of definition or rule to characterise the class [Lavine]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The iterative conception of set wasn't suggested until 1947 [Lavine]
The iterative conception needs the Axiom of Infinity, to show how far we can iterate [Lavine]
The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs [Lavine]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement [Lavine]
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
A collection is 'well-ordered' if there is a least element, and all of its successors can be identified [Lavine]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Mathematical proof by contradiction needs the law of excluded middle [Lavine]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
Every rational number, unlike every natural number, is divisible by some other number [Lavine]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Cauchy gave a necessary condition for the convergence of a sequence [Lavine]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
Counting results in well-ordering, and well-ordering makes counting possible [Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine]
The infinite is extrapolation from the experience of indefinitely large size [Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / c. Potential infinite
The intuitionist endorses only the potential infinite [Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
Ordinals are basic to Cantor's transfinite, to count the sets [Lavine]
Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory will found all of mathematics - except for the notion of proof [Lavine]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Intuitionism rejects set-theory to found mathematics [Lavine]
7. Existence / D. Theories of Reality / 4. Anti-realism
The realist/anti-realist debate is notoriously obscure and fruitless [Williamson]
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
There cannot be vague objects, so there may be no such thing as a mountain [Williamson]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Common sense and classical logic are often simultaneously abandoned in debates on vagueness [Williamson]
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
Modal thinking isn't a special intuition; it is part of ordinary counterfactual thinking [Williamson]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
Williamson can't base metaphysical necessity on the psychology of causal counterfactuals [Lowe on Williamson]
We scorn imagination as a test of possibility, forgetting its role in counterfactuals [Williamson]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
There are 'armchair' truths which are not a priori, because experience was involved [Williamson]
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
Intuition is neither powerful nor vacuous, but reveals linguistic or conceptual competence [Williamson]
When analytic philosophers run out of arguments, they present intuitions as their evidence [Williamson]
19. Language / A. Nature of Meaning / 6. Meaning as Use
You might know that the word 'gob' meant 'mouth', but not be competent to use it [Williamson]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
Most people think virtues can be displayed in bad actions [Foot]
Virtues are intended to correct design flaws in human beings [Foot, by Driver]
Actions can be in accordance with virtue, but without actually being virtuous [Foot]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / b. Basis of virtue
Virtues are corrective, to resist temptation or strengthen motivation [Foot]
23. Ethics / C. Virtue Theory / 3. Virtues / b. Temperance
Temperance is not a virtue if it results from timidity or excessive puritanism [Foot]
23. Ethics / C. Virtue Theory / 3. Virtues / d. Courage
Courage overcomes the fears which should be overcome, and doesn't overvalue personal safety [Foot]
24. Political Theory / B. Nature of a State / 5. Culture
If languages are intertranslatable, and cognition is innate, then cultures are all similar [Williamson]