25 ideas
1542 | Diogenes of Apollonia was the last natural scientist [Diogenes of Apollonia, by Simplicius] |
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] |
489 | Each thing must be in some way unique [Diogenes of Apollonia] |
483 | Start a thesis with something undisputable [Diogenes of Apollonia] |
1544 | Perception must be an internal matter, because we can fail to perceive when we are preoccupied [Diogenes of Apollonia, by Theophrastus] |
22371 | Determinism threatens free will if actions can be causally traced to external factors [Foot] |
24042 | The older Diogenes said the soul is air, made of the smallest particles [Diogenes of Apollonia] |
22372 | Not all actions need motives, but it is irrational to perform troublesome actions with no motive [Foot] |
22373 | People can act out of vanity without being vain, or even vain about this kind of thing [Foot] |
5995 | Diogenes of Apollonia offered the first teleological account of cosmology [Diogenes of Apollonia, by Robinson,TM] |
488 | Air is divine, because it is in and around everything, and arranges everything [Diogenes of Apollonia] |
484 | Everything is ultimately a variation of one underlying thing [Diogenes of Apollonia] |
486 | Plants and animals can only come into existence if something fixes their species [Diogenes of Apollonia] |
485 | Things must retain their essential nature during change, or mixing would be impossible [Diogenes of Apollonia] |