Combining Texts

All the ideas for 'Principles of Theoretical Logic', 'Foundations of Geometry' and 'fragments/reports'

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5 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]

5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism

10053

Geometrical axioms imply the propositions, but the former may not be true [Russell]

6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry

10052

Geometry is united by the intuitive axioms of projective geometry [Russell, by Musgrave]

26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / c. Ultimate substances

22745

Pherecydes said the first principle and element is earth [Pherecydes, by Sext.Empiricus]

29. Religion / D. Religious Issues / 2. Immortality / a. Immortality

5883	Pherecydes was the first to say that the soul is eternal [Pherecydes, by Cicero]