11 ideas
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] |
9541 | The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell] |
9543 | The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell] |
14212 | A consistent theory just needs one model; isomorphic versions will do too, and large domains provide those [Lewis] |
9544 | A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell] |
14213 | Anti-realists see the world as imaginary, or lacking joints, or beyond reference, or beyond truth [Lewis] |
14210 | A gerrymandered mereological sum can be a mess, but still have natural joints [Lewis] |
14215 | Causal theories of reference make errors in reference easy [Lewis] |
14209 | Descriptive theories remain part of the theory of reference (with seven mild modifications) [Lewis] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |