Combining Texts

All the ideas for 'fragments/reports', 'On Second-Order Logic' and 'What is Good?'

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14 ideas

1. Philosophy / C. History of Philosophy / 3. Earlier European Philosophy / c. Later medieval philosophy
Lucretius was rediscovered in 1417 [Grayling]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
'∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Many concepts can only be expressed by second-order logic [Boolos]
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
Musical performance can reveal a range of virtues [Damon of Ath.]
23. Ethics / C. Virtue Theory / 3. Virtues / e. Honour
In an honour code shame is the supreme punishment, and revenge is a duty [Grayling]
25. Social Practice / F. Life Issues / 4. Suicide
If suicide is lawful, but assisting suicide is unlawful, powerless people are denied their rights [Grayling]
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
Religion gives answers, comforts, creates social order, and panders to superstition [Grayling]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
To make an afterlife appealing, this life has to be denigrated [Grayling]
In Greek mythology only heroes can go to heaven [Grayling]