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Ideas for 'Writing the Book of the World', 'Sophistical Refutations' and 'Farewell to Reality: fairytale physics'

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2 ideas

5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives

15019	Define logical constants by role in proofs, or as fixed in meaning, or as topic-neutral [Sider]
	Full Idea: Some say that logical constants are those expressions that are defined by their proof-theoretic roles, others that they are the expressions whose semantic values are permutation-invariant, and still others that they are the topic-neutral expressions.
	From: Theodore Sider (Writing the Book of the World [2011], 10.3)
	A reaction: [He cites MacFarlane 2005 as giving a survey of this]

5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and

16967	'Are Coriscus and Callias at home?' sounds like a single question, but it isn't [Aristotle]
	Full Idea: If you ask 'Are Coriscus and Callias at home or not at home?', whether they are both at home or not there, the number of propositions is more than one. For if the answer is true, it does not follow that the question is a single one.
	From: Aristotle (Sophistical Refutations [c.331 BCE], 176a08)
	A reaction: [compressed] Aristotle is saying that some questions should not receive a 'yes' or 'no' answer, because they are equivocal. Arthur Prior cites this passage, on 'and'. Ordinary use of 'and' need not be the logical use of 'and'.