After enlightenment
Before Enlightenment chop wood, carry water. After enlightenment chop wood, carry water. -Zen Proverb
The softest things
The softest things in the world overcome the hardest things in the world. – Lao Tzu
The most important and fruitful concepts
In the world of human thought generally, and in physical science particularly, the most important and fruitful concepts are those to which it is impossible to attach a well-defined meaning. – H. A. Kramers