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] |
12750 | The question is whether force is self-sufficient in bodies, and essential, or dependent on something [Lenfant] |
9169 | A statement can be metaphysically necessary and epistemologically contingent [Putnam] |
5819 | Conceivability is no proof of possibility [Putnam] |
9168 | I can't distinguish elm trees, but I mean by 'elm' the same set of trees as everybody else [Putnam] |
5820 | 'Water' has an unnoticed indexical component, referring to stuff around here [Putnam] |
9170 | We need to recognise the contribution of society and of the world in determining reference [Putnam] |
5817 | Language is more like a cooperative steamship than an individual hammer [Putnam] |
5818 | If water is H2O in the actual world, there is no possible world where it isn't H2O [Putnam] |