22 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] |
16186 | The Barcan Formulas express how to combine modal operators with classical quantifiers [Simchen] |
16187 | The Barcan Formulas are orthodox, but clash with the attractive Actualist view [Simchen] |
16190 | BF implies that if W possibly had a child, then something is possibly W's child [Simchen] |
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] |
8439 | Maybe each event has only one possible causal history [Bennett] |
8440 | Maybe an event's time of occurrence is essential to it [Bennett] |
8978 | Events are made of other things, and are not fundamental to ontology [Bennett] |
16188 | Serious Actualism says there are no facts at all about something which doesn't exist [Simchen] |
8441 | Delaying a fire doesn't cause it, but hastening it might [Bennett] |
8436 | Either cause and effect are subsumed under a conditional because of properties, or it is counterfactual [Bennett] |
8435 | Causes are between events ('the explosion') or between facts/states of affairs ('a bomb dropped') [Bennett] |
10364 | Facts are about the world, not in it, so they can't cause anything [Bennett] |
8437 | The full counterfactual story asserts a series of events, because counterfactuals are not transitive [Bennett] |
8438 | A counterfactual about an event implies something about the event's essence [Bennett] |
8592 | Empty space is measurable in ways in which empty time necessarily is not [Bennett, by Shoemaker] |