7 ideas
| 9565 | Zermelo made 'set' and 'member' undefined axioms [Zermelo, by Chihara] |
| 3339 | For Zermelo's set theory the empty set is zero and the successor of each number is its unit set [Zermelo, by Blackburn] |
| 16978 | If conceivability is a priori coherence, that implies possibility [Tahko] |
| 11052 | Psychological logic can't distinguish justification from causes of a belief [Frege] |
| 16975 | Essences are used to explain natural kinds, modality, and causal powers [Tahko] |
| 16976 | Scientific essentialists tend to characterise essence in terms of modality (not vice versa) [Tahko] |
| 16977 | If essence is modal and laws are necessary, essentialist knowledge is found by scientists [Tahko] |