16 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] |
| 8361 | What is true used to be possible, but it may no longer be so [Wright,GHv] |
| 20751 | As a young girl assumes her status as feminine, she acts in a more fragile immobile way [Young,IM] |
| 8363 | p is a cause and q an effect (not vice versa) if manipulations of p change q [Wright,GHv] |
| 8364 | We can imagine controlling floods by controlling rain, but not vice versa [Wright,GHv] |
| 8366 | The very notion of a cause depends on agency and action [Wright,GHv] |
| 8362 | We give regularities a causal character by subjecting them to experiment [Wright,GHv] |
| 8360 | We must further analyse conditions for causation, into quantifiers or modal concepts [Wright,GHv] |
| 8365 | Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy) [Wright,GHv] |