Combining Texts

All the ideas for 'poems', 'The Problem of Possibilia' and 'works'

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8 ideas

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]

10. Modality / B. Possibility / 1. Possibility

9212	Possible states of affairs are not propositions; a proposition can't be a state of affairs! [Fine,K]

10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds

9213	The actual world is a possible world, so we can't define possible worlds as 'what might have been' [Fine,K]

22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention

6017	Nomos is king [Pindar]