23 ideas
19695 | The devil was wise as an angel, and lost no knowledge when he rebelled [Whitcomb] |
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] |
15091 | Restrict 'logical truth' to formal logic, rather than including analytic and metaphysical truths [Shoemaker] |
10590 | Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro] |
10292 | Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro] |
10297 | The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro] |
10296 | The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro] |
10294 | Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro] |
15095 | A property's causal features are essential, and only they fix its identity [Shoemaker] |
15097 | I claim that a property has its causal features in all possible worlds [Shoemaker] |
10591 | Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro] |
15094 | I now deny that properties are cluster of powers, and take causal properties as basic [Shoemaker] |
15099 | If something is possible, but not nomologically possible, we need metaphysical possibility [Shoemaker] |
15101 | Once you give up necessity as a priori, causal necessity becomes the main type of necessity [Shoemaker] |
15098 | Empirical evidence shows that imagining a phenomenon can show it is possible [Shoemaker] |
15100 | Imagination reveals conceptual possibility, where descriptions avoid contradiction or incoherence [Shoemaker] |
15096 | 'Grue' only has causal features because of its relation to green [Shoemaker] |
15093 | We might say laws are necessary by combining causal properties with Armstrong-Dretske-Tooley laws [Shoemaker] |