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] |
| 8568 | A property is merely a constituent of laws of nature; temperature is just part of thermodynamics [Mellor] |
| 8564 | There is obviously a possible predicate for every property [Mellor] |
| 8566 | We need universals for causation and laws of nature; the latter give them their identity [Mellor] |
| 8565 | If properties were just the meanings of predicates, they couldn't give predicates their meaning [Mellor] |
| 14797 | Vagueness is a neglected but important part of mathematical thought [Peirce] |
| 14798 | All communication is vague, and is outside the principle of non-contradiction [Peirce] |
| 8567 | Singular causation requires causes to raise the physical probability of their effects [Mellor] |