13 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] |
| 22352 | Out of more than a hundred planets, Earth is the only one with the idea of free will [Vonnegut] |
| 23395 | Mohists desire wealth, population and social order as the best consequences [Mozi, by Norden] |
| 23394 | If people regarded other states as they did their own, they would never attack them [Mozi] |
| 23396 | Mozi condemns partiality, which is the cause of all the great harms in the world [Mozi] |
| 23397 | Those who are against impartiality still prefer impartial protectors [Mozi] |