38 ideas
3750 | "It is true that x" means no more than x [Ramsey] |
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] |
13430 | Infinity: there is an infinity of distinguishable individuals [Ramsey] |
13428 | Reducibility: to every non-elementary function there is an equivalent elementary function [Ramsey] |
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] |
13427 | Either 'a = b' vacuously names the same thing, or absurdly names different things [Ramsey] |
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] |
13334 | Contradictions are either purely logical or mathematical, or they involved thought and language [Ramsey] |
6409 | The 'simple theory of types' distinguishes levels among properties [Ramsey, by Grayling] |
13426 | Formalists neglect content, but the logicists have focused on generalizations, and neglected form [Ramsey] |
13425 | Formalism is hopeless, because it focuses on propositions and ignores concepts [Ramsey] |
8495 | The distinction between particulars and universals is a mistake made because of language [Ramsey] |
8493 | We could make universals collections of particulars, or particulars collections of their qualities [Ramsey] |
8494 | Obviously 'Socrates is wise' and 'Socrates has wisdom' express the same fact [Ramsey] |
8361 | What is true used to be possible, but it may no longer be so [Wright,GHv] |
13766 | 'If' is the same as 'given that', so the degrees of belief should conform to probability theory [Ramsey, by Ramsey] |
10993 | Ramsey's Test: believe the consequent if you believe the antecedent [Ramsey, by Read] |
14279 | Asking 'If p, will q?' when p is uncertain, then first add p hypothetically to your knowledge [Ramsey] |
3212 | Beliefs are maps by which we steer [Ramsey] |
22328 | I just confront the evidence, and let it act on me [Ramsey] |
22325 | A belief is knowledge if it is true, certain and obtained by a reliable process [Ramsey] |
19724 | Belief is knowledge if it is true, certain, and obtained by a reliable process [Ramsey] |
6894 | Mental terms can be replaced in a sentence by a variable and an existential quantifier [Ramsey] |
19143 | Ramsey gave axioms for an uncertain agent to decide their preferences [Ramsey, by Davidson] |
18818 | Sentence meaning is given by the actions to which it would lead [Ramsey] |
8363 | p is a cause and q an effect (not vice versa) if manipulations of p change q [Wright,GHv] |
8364 | We can imagine controlling floods by controlling rain, but not vice versa [Wright,GHv] |
8366 | The very notion of a cause depends on agency and action [Wright,GHv] |
8362 | We give regularities a causal character by subjecting them to experiment [Wright,GHv] |
8360 | We must further analyse conditions for causation, into quantifiers or modal concepts [Wright,GHv] |
8365 | Some laws are causal (Ohm's Law), but others are conceptual principles (conservation of energy) [Wright,GHv] |
9418 | All knowledge needs systematizing, and the axioms would be the laws of nature [Ramsey] |
9420 | Causal laws result from the simplest axioms of a complete deductive system [Ramsey] |