Combining Texts

All the ideas for 'fragments/reports', 'An Introduction to Modal Logic' and 'Putnam's Paradox'

expand these ideas     |    start again     |     specify just one area for these texts


11 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 / J. Model Theory in Logic / 2. Isomorphisms
A consistent theory just needs one model; isomorphic versions will do too, and large domains provide those [Lewis]
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]
7. Existence / D. Theories of Reality / 4. Anti-realism
Anti-realists see the world as imaginary, or lacking joints, or beyond reference, or beyond truth [Lewis]
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
A gerrymandered mereological sum can be a mess, but still have natural joints [Lewis]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Causal theories of reference make errors in reference easy [Lewis]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
Descriptive theories remain part of the theory of reference (with seven mild modifications) [Lewis]
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]