Combining Texts

All the ideas for 'fragments/reports', 'The Approach to Metaphysics' and 'works'

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9 ideas

1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science

14799

Metaphysics rests on observations, but ones so common we hardly notice them [Peirce]

5. Theory of Logic / A. Overview of Logic / 2. History of Logic

11022

Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read]

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

11065

The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna]

11023

The logical connectives are 'defined' by their introduction rules [Gentzen]

11213

Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen]

6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic

10067

Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave]

7. Existence / A. Nature of Existence / 3. Being / d. Non-being

18933

Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]

19. Language / F. Communication / 1. Rhetoric

5864	Destroy seriousness with laughter, and laughter with seriousness [Gorgias]

9866	Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]