Combining Texts

All the ideas for 'Lysis', 'A Priori Knowledge Revisited' and 'An Introduction to Modal Logic'

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10 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 / A. Overview of Logic / 6. Classical Logic
Classical logic is our preconditions for assessing empirical evidence [Kitcher]
I believe classical logic because I was taught it and use it, but it could be undermined [Kitcher]
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]
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
Many necessities are inexpressible, and unknowable a priori [Kitcher]
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
Knowing our own existence is a priori, but not necessary [Kitcher]
22. Metaethics / C. The Good / 1. Goodness / a. Form of the Good
The good is beautiful [Plato]
23. Ethics / C. Virtue Theory / 4. External Goods / d. Friendship
People say that friendship exists only between good men [Plato]