26 ideas
| 21855 | Only in the 1780s did it become acceptable to read Spinoza [Lord] |
| 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] |
| 21866 | Hobbes and Spinoza use 'conatus' to denote all endeavour for advantage in nature [Lord] |
| 20289 | Ethics is universalisable - it must involve an impartial and universal view of things [Singer] |
| 20286 | Following an inner voice for morality is irresponsible in a rational agent [Singer] |
| 20282 | The sanctity of a human life depends either on being of our species, or on being a person [Singer] |
| 20278 | 'Marginal utility' says something is more useful if it is in short supply [Singer] |
| 20281 | Why should I do anything for posterity? What has posterity ever done for me? [Singer] |
| 20276 | Conflict of rules might be avoided by greater complexity, or by a hierarchy of rules [Singer] |
| 20290 | Psychopaths may just be bored, because they cannot participate in normal emotional life [Singer] |
| 20288 | You can't condemn violent revolution without assessing the evils it prevents [Singer] |
| 21997 | In Marxism the state will be superseded [Singer] |
| 20287 | If 49% of the population can be wrong, so can 51% [Singer] |
| 21993 | Materialist history says we are subject to incomprehensible forces [Singer] |
| 20277 | Equality of interests is a minimal principle, not implying equal treatment [Singer] |
| 20279 | Equality of opportunity unfairly rewards those lucky enough to have great ability [Singer] |
| 20285 | If a right entails having the relevant desire, many creatures might have no right to life [Singer] |
| 20284 | Why should a potential person have the rights of an actual person? [Singer] |
| 20283 | Killing a chimp is worse than killing a human too defective to be a person [Singer] |