3 ideas
| 22110 | Demonstration provides depth of understanding and explanation (rather than foundations) [Kretzmann/Stump] |
| 7634 | Icons resemble their subject, an index is a natural sign, and symbols are conventional [Peirce, by Maund] |
| 9425 | Lewis later proposed the axioms at the intersection of the best theories (which may be few) [Mumford on Lewis] |