Who said "A soldier's duty is to obey, but a leader's duty is to think."?

This quote is attributed to Douglas Haig.

A soldier's duty is to obey, but a leader's duty is to think... - Douglas Haig

"A soldier's duty is to obey, but a leader's duty is to think."

Douglas Haig Leadership

Military Field Marshal British 1861–1928

"I have not the smallest doubt that the credit of this war will eventually rest with the cavalry."

"The general who loses morale loses the battle."

"In any war, the morale of the troops is half the battle."

"Success in war depends upon the moral factor."

"A leader must be fair and just."

"Integrity is everything."

"One must take responsibility for one's environment."

"In this house, I make the decisions"