15 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] |
| 10242 | I apply structuralism to concrete and abstract objects indiscriminately [Quine] |
| 10243 | My ontology is quarks etc., classes of such things, classes of such classes etc. [Quine] |
| 13169 | I call Aristotle's entelechies 'primitive forces', which originate activity [Leibniz] |
| 13168 | My formal unifying atoms are substantial forms, which are forces like appetites [Leibniz] |
| 13170 | The analysis of things leads to atoms of substance, which found both composition and action [Leibniz] |
| 13171 | Substance must necessarily involve progress and change [Leibniz] |
| 13167 | We need the metaphysical notion of force to explain mechanics, and not just extended mass [Leibniz] |