Who said "The soldier's greatest enemy is often his own doubt."?

This quote is attributed to Qi Jiguang.

The soldier's greatest enemy is often his own doubt. - Qi Jiguang

"The soldier's greatest enemy is often his own doubt."

Qi Jiguang Fear

Military General Chinese 1528–1588

"The art of war is of vital importance to the State. It is the means upon which the State depends for its preservation."

"All warfare is based on deception."

"Know yourself and know your enemy; in a hundred battles, you will never be defeated."

"The supreme art of war is to subdue the enemy without fighting."

"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."