31 ideas
| 18806 | Frege thought traditional categories had psychological and linguistic impurities [Frege, by Rumfitt] |
| 8490 | First-level functions have objects as arguments; second-level functions take functions as arguments [Frege] |
| 8492 | Relations are functions with two arguments [Frege] |
| 8487 | Arithmetic is a development of logic, so arithmetical symbolism must expand into logical symbolism [Frege] |
| 18899 | Frege takes the existence of horses to be part of their concept [Frege, by Sommers] |
| 17377 | All descriptive language is classificatory [Dupré] |
| 17376 | We should aim for a classification which tells us as much as possible about the object [Dupré] |
| 4028 | Frege allows either too few properties (as extensions) or too many (as predicates) [Mellor/Oliver on Frege] |
| 8489 | The concept 'object' is too simple for analysis; unlike a function, it is an expression with no empty place [Frege] |
| 17390 | Natural kinds don't need essentialism to be explanatory [Dupré] |
| 17389 | A species might have its essential genetic mechanism replaced by a new one [Dupré] |
| 17388 | It seems that species lack essential properties, so they can't be natural kinds [Dupré] |
| 17374 | The possibility of prediction rests on determinism [Dupré] |
| 17378 | Presumably molecular structure seems important because we never have the Twin Earth experience [Dupré] |
| 9947 | Concepts are the ontological counterparts of predicative expressions [Frege, by George/Velleman] |
| 10319 | An assertion about the concept 'horse' must indirectly speak of an object [Frege, by Hale] |
| 8488 | A concept is a function whose value is always a truth-value [Frege] |
| 9948 | Unlike objects, concepts are inherently incomplete [Frege, by George/Velleman] |
| 4972 | I may regard a thought about Phosphorus as true, and the same thought about Hesperus as false [Frege] |
| 7453 | Galen's medicine followed the mean; each illness was balanced by opposite treatment [Galen, by Hacking] |
| 17381 | Phylogenetics involves history, and cladism rests species on splits in lineage [Dupré] |
| 17385 | Kinds don't do anything (including evolve) because they are abstract [Dupré] |
| 17375 | Natural kinds are decided entirely by the intentions of our classification [Dupré] |
| 17379 | Borders between species are much less clear in vegetables than among animals [Dupré] |
| 17384 | Even atoms of an element differ, in the energy levels of their electrons [Dupré] |
| 17387 | Ecologists favour classifying by niche, even though that can clash with genealogy [Dupré] |
| 17380 | Wales may count as fish [Dupré] |
| 17382 | Cooks, unlike scientists, distinguish garlic from onions [Dupré] |
| 17383 | Species are the lowest-level classification in biology [Dupré] |
| 17386 | The theory of evolution is mainly about species [Dupré] |
| 8491 | The Ontological Argument fallaciously treats existence as a first-level concept [Frege] |