27 ideas
6118 | Philosophy is logical analysis, followed by synthesis [Russell] |
6116 | A logical language would show up the fallacy of inferring reality from ordinary language [Russell] |
6117 | Philosophy should be built on science, to reduce error [Russell] |
10301 | The axiom of choice is controversial, but it could be replaced [Shapiro] |
6110 | Subject-predicate logic (and substance-attribute metaphysics) arise from Aryan languages [Russell] |
6107 | It is logic, not metaphysics, that is fundamental to philosophy [Russell] |
10588 | First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro] |
10298 | Some say that second-order logic is mathematics, not logic [Shapiro] |
10299 | If the aim of logic is to codify inferences, second-order logic is useless [Shapiro] |
10300 | Logical consequence can be defined in terms of the logical terminology [Shapiro] |
6115 | Vagueness, and simples being beyond experience, are obstacles to a logical language [Russell] |
10290 | Second-order variables also range over properties, sets, relations or functions [Shapiro] |
10590 | Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro] |
10296 | The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro] |
10297 | The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro] |
10292 | Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro] |
6109 | Some axioms may only become accepted when they lead to obvious conclusions [Russell] |
10294 | Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro] |
6108 | Maths can be deduced from logical axioms and the logic of relations [Russell] |
10968 | Russell gave up logical atomism because of negative, general and belief propositions [Russell, by Read] |
6113 | To mean facts we assert them; to mean simples we name them [Russell] |
6114 | 'Simples' are not experienced, but are inferred at the limits of analysis [Russell] |
21722 | Better to construct from what is known, than to infer what is unknown [Russell] |
6111 | As propositions can be put in subject-predicate form, we wrongly infer that facts have substance-quality form [Russell] |
10591 | Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro] |
22200 | If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle] |
6112 | Meaning takes many different forms, depending on different logical types [Russell] |