that’s where you really spot a fighter’s mettle,
where the brave and craven always show their stripes.
The skin of the coward changes calor all the time,
he can’t get a grip on himself, he can’t sit still,
he squats and rocks, shifting his weight from foot to foot,
his heart racing, pounding inside the fellow’s ribs,
his teeth chattering – he dreads some grisly death.
But the skin of the brave soldier never blanches.
He’s all control. Tense but no great fear.
The moment he joins his comrades packed in ambush
he prays to wade in carnage, cut-and-thrust at once.

– Homer

The Iliad, Book 13, lines 327-337. Idomeneus tells Meriones that war reveals the true nature of a fighter, and separates the brave man from the coward. The brave man is unafraid and all control and can handle the stresses of war. But the coward falls apart under the pressure, dreading grisly death.