19 ideas
10301 | The axiom of choice is controversial, but it could be replaced [Shapiro] |
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] |
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] |
10294 | Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro] |
10591 | Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro] |
15959 | If the substantial form of brass implies its stability, how can it melt and remain brass? [Alexander,P] |
15956 | The peripatetics treated forms and real qualities as independent of matter, and non-material [Alexander,P] |
15975 | Can the qualities of a body be split into two groups, where the smaller explains the larger? [Alexander,P] |
8991 | Foucault can't accept that power is sometimes decent and benign [Foucault, by Scruton] |
15963 | Science has been partly motivated by the belief that the universe is run by God's laws [Alexander,P] |
15951 | Alchemists tried to separate out essences, which influenced later chemistry [Alexander,P] |
15981 | Absolute space either provides locations, or exists but lacks 'marks' for locations [Alexander,P] |