Combining Texts

All the ideas for 'Letters to Edward Stillingfleet', 'Letters to Thomasius' and 'An Introduction to Modal Logic'

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8 ideas

4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
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
The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
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
A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
9. Objects / D. Essence of Objects / 1. Essences of Objects
The essence of a circle is the equality of its radii [Leibniz]
9. Objects / D. Essence of Objects / 3. Individual Essences
Every individual thing which exists has an essence, which is its internal constitution [Locke]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
If it is knowledge, it is certain; if it isn't certain, it isn't knowledge [Locke]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Bodies are recreated in motion, and don't exist in intervening instants [Leibniz]