无冥冥之志者，无昭昭之明；无惛惛之事者，无赫赫之功。
没有刻苦钻研的精神，就不能明辨事情的道理；没有专心致志的工作，就不会取得显赫的成绩。
If you're not stubborn， you'll give up on experiments too soon. And if you're not flexible， you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.
Myth is a type of speech chosen by history: it cannot possibly evolve from the 'nature' of things.