7 ideas
| 8203 | All the arithmetical entities can be reduced to classes of integers, and hence to sets [Quine] |
| 12741 | If experience is just a dream, it is still real enough if critical reason is never deceived [Leibniz] |
| 12740 | The strongest criterion that phenomena show reality is success in prediction [Leibniz] |
| 12721 | Light, heat and colour are apparent qualities, and so are motion, figure and extension [Leibniz] |
| 20643 | Consilience is a common groundwork of explanation [Whewell] |
| 8202 | Meaning is essence divorced from things and wedded to words [Quine] |
| 8201 | The distinction between meaning and further information is as vague as the essence/accident distinction [Quine] |