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] |
| 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] |
| 21515 | Incoherence may be more important for enquiry than coherence [Olsson] |
| 21514 | Coherence is the capacity to answer objections [Olsson] |
| 21496 | Mere agreement of testimonies is not enough to make truth very likely [Olsson] |
| 21499 | Coherence is only needed if the information sources are not fully reliable [Olsson] |
| 21502 | A purely coherent theory cannot be true of the world without some contact with the world [Olsson] |
| 21512 | Extending a system makes it less probable, so extending coherence can't make it more probable [Olsson] |
| 22395 | Moral judgements are hypothetical, because they depend on interests and desires [Foot] |