21 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] |
13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
22189 | Why abandon a theory if you don't have a better one? [Gorham] |
22190 | If a theory is more informative it is less probable [Gorham] |
22192 | Is Newton simpler with universal simultaneity, or Einstein simpler without absolute time? [Gorham] |
22194 | Structural Realism says mathematical structures persist after theory rejection [Gorham] |
22195 | Structural Realists must show the mathematics is both crucial and separate [Gorham] |
22197 | Theories aren't just for organising present experience if they concern the past or future [Gorham] |
22196 | For most scientists their concepts are not just useful, but are meant to be true and accurate [Gorham] |
22193 | Consilience makes the component sciences more likely [Gorham] |
22198 | Aristotelian physics has circular celestial motion and linear earthly motion [Gorham] |