When a man seats before his eyes the bronze face of his helmet and steps off from the line of departure, he divides himself, as he divides his ‘ticket.’ into two parts.  One part he leaves behind.  That part which takes delight in his children, which lifts his voice in the chorus, which clasps his wife to him in the sweet darkness of their bed.

“That half of him, the best part, a man sets aside and leaves behind.  He banishes from his heart all feelings of tenderness and mercy, all compassion and kindness, all thought or concept of the enemy as a man, a human being like himself.  He marches into battle bearing only the second portion of himself, the baser measure, that half which knows slaughter and butchery and turns to blind eye to quarter.  He could not fight at all if he did not do this. . .

“Then this man returns, alive, out of the slaughter. . . He reclaims that part of himself which he had earlier set aside.

Gates of Fire, Steven Pressfield, pp. 131-132.  The speech of Leonidas after the battle near Antirhion.