Quote by Confucius
"A gem cannot be polished without friction, nor man perfected without trials."
More from Confucius
"The man who moves a mountain begins by carrying away small stones."
"It does not matter how slowly you go as long as you do not stop."
"The superior man thinks always of virtue, the common man thinks of comfort."
"When you know a thing, to hold that you know it; and when you do not know a thing, to allow that you do not know it - this is knowledge."