5 ideas
| 579 | Cratylus said you couldn't even step into the same river once [Cratylus, by Aristotle] |
| 578 | Cratylus decided speech was hopeless, and his only expression was the movement of a finger [Cratylus, by Aristotle] |
| 22363 | You have only begun to do real science when you can express it in numbers [Kelvin] |
| 6004 | The cardinal virtues are theoretical (based on knowledge), and others are 'non-theoretical' [Hecato, by Dorandi] |
| 20644 | Energy has progressed from a mere formula, to a principle pervading all nature [Kelvin] |