Combining Texts

All the ideas for 'The Sign of Four', 'An Axiomatization of Set Theory' and 'works'

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5 ideas

2. Reason / B. Laws of Thought / 2. Sufficient Reason
Sufficient reason is implied by contradiction, of an insufficient possible which exists [Wolff, by Korsgaard]
     Full Idea: Wolff believed that the principle of sufficient reason could be derived from the principle of contradiction, for there would be a contradiction in the insufficiently determined existence of a merely possible thing.
     From: report of Christian Wolff (works [1730]) by Christine M. Korsgaard - Intro to Ethics, Politics, Religion in Kant 'A child'
     A reaction: Sounds as if he might be begging to question. You would only protest against the insufficient determination of something if you already believed in the principle of sufficient reason. Nice try.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of Size is not self-evident, and seems too strong [Lavine on Neumann]
     Full Idea: Von Neumann's Limitation of Size axiom is not self-evident, and he himself admitted that it seemed too strong.
     From: comment on John von Neumann (An Axiomatization of Set Theory [1925]) by Shaughan Lavine - Understanding the Infinite VII.1
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
All the axioms for mathematics presuppose set theory [Neumann]
     Full Idea: There is no axiom system for mathematics, geometry, and so forth that does not presuppose set theory.
     From: John von Neumann (An Axiomatization of Set Theory [1925]), quoted by Stewart Shapiro - Foundations without Foundationalism 8.2
     A reaction: Von Neumann was doubting whether set theory could have axioms, and hence the whole project is doomed, and we face relativism about such things. His ally was Skolem in this.
14. Science / C. Induction / 1. Induction
If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle]
     Full Idea: When you have eliminated the impossible, whatever remains, however improbable, must be the truth.
     From: Arthur Conan Doyle (The Sign of Four [1890], Ch. 6)
     A reaction: A beautiful statement, by Sherlock Holmes, of Eliminative Induction. It is obviously not true, of course. Many options may still face you after you have eliminated what is actually impossible.
28. God / A. Divine Nature / 6. Divine Morality / b. Euthyphro question
Confucius shows that ethics can rest on reason, rather than on revelation [Wolff, by Korsgaard]
     Full Idea: Wolff claimed that the moral philosophy of Confucius shows that ethics is accessible to natural reason and independent of revelation.
     From: report of Christian Wolff (works [1730]) by Christine M. Korsgaard - Intro to Ethics, Politics, Religion in Kant 'A child'
     A reaction: Wolff was banished for proposing this idea.