24 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] |
10245 | One geometry cannot be more true than another [Poincaré] |
15923 | Poincaré rejected the actual infinite, claiming definitions gave apparent infinity to finite objects [Poincaré, by Lavine] |
10180 | Mathematicians do not study objects, but relations between objects [Poincaré] |
9916 | Convention, yes! Arbitrary, no! [Poincaré, by Putnam] |
18203 | Avoid non-predicative classifications and definitions [Poincaré] |
19284 | Asserting a necessity just expresses our inability to imagine it is false [Blackburn] |
14629 | If we are told the source of necessity, this seems to be a regress if the source is not already necessary [Blackburn] |
14529 | If something underlies a necessity, is that underlying thing necessary or contingent? [Blackburn, by Hale/Hoffmann,A] |
6451 | Visual sense data are an inner picture show which represents the world [Blackburn] |
2866 | A true belief might be based on a generally reliable process that failed on this occasion [Blackburn] |
23996 | Akrasia is intelligible in hindsight, when we revisit our previous emotions [Blackburn] |
11911 | Some philosophers always want more from morality; for others, nature is enough [Blackburn] |
2864 | The main objection to intuitionism in ethics is that intuition is a disguise for prejudice or emotion [Blackburn] |
2865 | Critics of prescriptivism observe that it is consistent to accept an ethical verdict but refuse to be bound by it [Blackburn] |
23223 | The word 'respect' ranges from mere non-interference to the highest levels of reverence [Blackburn] |
15877 | The aim of science is just to create a comprehensive, elegant language to describe brute facts [Poincaré, by Harré] |