7 ideas
| 6004 | The cardinal virtues are theoretical (based on knowledge), and others are 'non-theoretical' [Hecato, by Dorandi] |
| 22439 | There are only duties if there are rights, so truth is only for those with a right to it [Constant] |
| 22440 | Unconditional truth-telling makes a society impossible [Constant] |
| 17402 | Mendeleev saw three principles in nature: matter, force and spirit (where the latter seems to be essence) [Mendeleev, by Scerri] |
| 17399 | Elements don't survive in compounds, but the 'substance' of the element does [Mendeleev] |
| 17400 | Mendeleev focused on abstract elements, not simple substances, so he got to their essence [Mendeleev, by Scerri] |
| 17401 | Mendeleev had a view of elements which allowed him to overlook some conflicting observations [Mendeleev] |