Combining Texts

All the ideas for 'fragments/reports', 'The Laws of Thought' and 'The Theory of Logical Types'

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10 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic

8083	Boole applied normal algebra to logic, aiming at an algebra of thought [Boole, by Devlin]

7727	Boole's notation can represent syllogisms and propositional arguments, but not both at once [Boole, by Weiner]

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

8686	Boole made logic more mathematical, with algebra, quantifiers and probability [Boole, by Friend]

5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic

21566

'Propositional functions' are ambiguous until the variable is given a value [Russell]

5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof

22277

Boole's method was axiomatic, achieving economy, plus multiple interpretations [Boole, by Potter]

5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox

21567

'All judgements made by Epimenedes are true' needs the judgements to be of the same type [Russell]

6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory

23457

Type theory cannot identify features across levels (because such predicates break the rules) [Morris,M on Russell]

21556

Classes are defined by propositional functions, and functions are typed, with an axiom of reducibility [Russell, by Lackey]

6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism

21568

A one-variable function is only 'predicative' if it is one order above its arguments [Russell]

10. Modality / A. Necessity / 8. Transcendental Necessity

490	Everything happens by reason and necessity [Leucippus]