18 ideas
| 9254 | In philosophy the truth can only be reached via the ruins of the false [Prichard] |
| 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] |
| 4688 | We imagine small and large objects scaled to the same size, suggesting a fixed capacity for imagination [Lavers] |
| 9261 | The 'Ethics' is disappointing, because it fails to try to justify our duties [Prichard] |
| 9262 | The mistake is to think we can prove what can only be seen directly in moral thinking [Prichard] |
| 9256 | I see the need to pay a debt in a particular instance, and any instance will do [Prichard] |
| 9257 | The complexities of life make it almost impossible to assess morality from a universal viewpoint [Prichard] |
| 9260 | Virtues won't generate an obligation, so it isn't a basis for morality [Prichard] |
| 9259 | We feel obligations to overcome our own failings, and these are not relations to other people [Prichard] |
| 9255 | Seeing the goodness of an effect creates the duty to produce it, not the desire [Prichard] |
| 9258 | If pain were instrinsically wrong, it would be immoral to inflict it on ourselves [Prichard] |