Combining Texts

All the ideas for 'Letters to Thomas Burnett', 'An Introduction to Modal Logic' and 'Preface to 'De Revolutionibus''

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7 ideas

4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
9540 A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
9541 The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
9543 The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]
5. Theory of Logic / K. Features of Logics / 4. Completeness
9544 A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
13197 The notion of substance is one of the keys to true philosophy [Leibniz]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
15282 Facts should be deducible from the theory and initial conditions, and prefer the simpler theory [Osiander, by Harré/Madden]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
13198 Gravity is within matter because of its structure, and it can be explained. [Leibniz]