14 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] |
| 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] |
| 12695 | Epicurean atomists say body is sensible, to distinguish it from space. [Garber] |
| 23569 | The only just cause for a war is a wrong received [Vitoria] |
| 23601 | Leaders can only attack foreigners who have done wrong (as with their own subjects) [Vitoria] |
| 23566 | Princes should not justify a war to their subjects, and doing so would undermine the state [Vitoria] |
| 23576 | Sacking a city is lawful if it motivates the attacking troops [Vitoria] |
| 12705 | Epicurean atoms are distinguished by their extreme hardness [Garber] |