18 ideas
| 6396 | A sentence is held true because of a combination of meaning and belief [Davidson] |
| 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] |
| 579 | Cratylus said you couldn't even step into the same river once [Cratylus, by Aristotle] |
| 11145 | Having a belief involves the possibility of being mistaken [Davidson] |
| 6397 | The concept of belief can only derive from relationship to a speech community [Davidson] |
| 578 | Cratylus decided speech was hopeless, and his only expression was the movement of a finger [Cratylus, by Aristotle] |
| 6392 | Thought depends on speech [Davidson] |
| 6393 | A creature doesn't think unless it interprets another's speech [Davidson] |
| 11144 | Concepts are only possible in a language community [Davidson] |
| 6395 | An understood sentence can be used for almost anything; it isn't language if it has only one use [Davidson] |
| 6394 | The pattern of sentences held true gives sentences their meaning [Davidson] |