Combining Texts

All the ideas for 'Principles of Theoretical Logic', 'Reply to Professor Frankena' and 'Realism, Mathematics and Modality'

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3 ideas

4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC

17750

The first clear proof of the consistency of the first order predicate logic was in 1928 [Hilbert/Ackermann, by Walicki]

6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics

8714	Fictionalists say 2+2=4 is true in the way that 'Oliver Twist lived in London' is true [Field,H]

23. Ethics / D. Deontological Ethics / 4. Categorical Imperative

22395

Moral judgements are hypothetical, because they depend on interests and desires [Foot]