The word courage seems to come from the two French words coeur, meaning heart, and rage, meaning pronounced anger. Courage as rage du coeur (anger of the heart)?
Courage is arguably more important than knowledge since, as Churchill pointed out, without courage all the other virtues are likely to wither away at the slightest hint of suppression.
It is courage that makes one stand up against what's wrong, disobey immoral laws and go out and beyond one's comfort zone to do what is right.
Order followers, such as the Nazis in their droves, were cowards, despite the illusion one might have that they were fighting for what they thought to be right.
Like group mentality where fearful bullies pick on those beneath them to protect their own person within the dynamics of the group, order followers generally are afraid to say no and resist the immoral deeds they are ordered to do.
As one French policeman put it to a friend of mine
'Penser, c'est désobéir.'To think is to disobey.
Indeed, Hannah Arendt was right to state in her book The Human Condition that to think is to resist and it is easier not to think under conditions of tyranny and simply comply and follow along than it is to question and resist those conditions.