Who said "A warrior's greatest enemy is often his own doubt."?

This quote is attributed to Shang.

A warrior's greatest enemy is often his own doubt. - Shang

"A warrior's greatest enemy is often his own doubt."

Shang Fear

"A man doesn't speak unless he has something to say."

"I need a man who can act like a woman."

"You fight good."

"Prepare yourself. The Huns have invaded China."

"Face your fears with courage."

"You can't live your life in fear."

"Snakes. Why'd it have to be snakes?"

"Fear is just another obstacle to overcome."