13 ideas
| 11257 | The Pythagoreans were the first to offer definitions [Politis, by Politis] |
| 11235 | 'True of' is applicable to things, while 'true' is applicable to words [Politis] |
| 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] |
| 11277 | Maybe 'What is being? is confusing because we can't ask what non-being is like [Politis] |
| 11248 | Necessary truths can be two-way relational, where essential truths are one-way or intrinsic [Politis] |
| 7489 | Joshua said, Sun, stand thou still [Anon (Josh)] |