22 ideas
291 | Don't assume that wisdom is the automatic consequence of old age [Plato] |
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] |
13931 | By using aporiai as his start, Aristotle can defer to the wise, as well as to the many [Haslanger] |
10294 | Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro] |
13925 | Ontology disputes rest on more basic explanation disputes [Haslanger] |
10591 | Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro] |
13924 | The persistence of objects seems to be needed if the past is to explain the present [Haslanger] |
13930 | Persistence makes change and its products intelligible [Haslanger] |
13927 | We must explain change amongst 'momentary entities', or else the world is inexplicable [Haslanger] |
13928 | If the things which exist prior to now are totally distinct, they need not have existed [Haslanger] |
13929 | Natural explanations give the causal interconnections [Haslanger] |
13926 | Best explanations, especially natural ones, need grounding, notably by persistent objects [Haslanger] |
293 | Being unafraid (perhaps through ignorance) and being brave are two different things [Plato] |