7 ideas
| 10496 | Monothetic categories have fixed defining features, and polythetic categories do not [Ellen] |
| 10497 | In symbolic classification, the categories are linked to rules [Ellen] |
| 10494 | Several words may label a category; one word can name several categories; some categories lack words [Ellen] |
| 10495 | Continuous experience sometimes needs imposition of boundaries to create categories [Ellen] |
| 12887 | A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim] |
| 10498 | Classification is no longer held to be rooted in social institutions [Ellen] |
| 5692 | Introspection is not perception, because there are no extra qualities apart from the mental events themselves [Rosenthal] |