14 ideas
13407 | All worthwhile philosophy is synthetic theorizing, evaluated by experience [Papineau] |
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] |
13409 | Our best theories may commit us to mathematical abstracta, but that doesn't justify the commitment [Papineau] |
13406 | A priori knowledge is analytic - the structure of our concepts - and hence unimportant [Papineau] |
13408 | Intuition and thought-experiments embody substantial information about the world [Papineau] |
19413 | If we know what is good or rational, our knowledge is extended, and our free will restricted [Leibniz] |
13410 | Verificationism about concepts means you can't deny a theory, because you can't have the concept [Papineau] |