Some men think because they're afraid to do.

Bran thought about it. 'Can a man still be brave if he's afraid?'
'That is the only time a man can be brave,' his father told him.

Let his sword break and his shield shatter, Sansa thought coldly as she shoved out through the doors, let his courage fail him and every man desert him.

It was queer how sometimes a child's innocent eyes can see things that grown men are blind to.

Small men oft feel a need to prove their courage with unseemly boasts," he declared. "I doubt if he could kill a duck."
Tyrion shrugged. "Fetch the duck.

It is not the strength of the body that counts, but the strength of the spirit.