15 ideas
13913 | The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward] |
13914 | Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward] |
13915 | Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward] |
13916 | Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward] |
10247 | We have no adequate logic at the moment, so mathematicians must create one [Veblen] |
13850 | In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward] |
13849 | Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward] |
13851 | Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward] |
13852 | Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward] |
12608 | Concepts are distinguished by roles in judgement, and are thus tied to rationality [Peacocke] |
12605 | A sense is individuated by the conditions for reference [Peacocke] |
12607 | Fregean concepts have their essence fixed by reference-conditions [Peacocke] |
12609 | Concepts have distinctive reasons and norms [Peacocke] |
12604 | Any explanation of a concept must involve reference and truth [Peacocke] |
12610 | Encountering novel sentences shows conclusively that meaning must be compositional [Peacocke] |