Who is it who decides that one man should live and another should die? My life wasn't worth any more than his, but he's the one who's buried, while I… - Christopher Paolini

"Left weaponless, Roran was forced to retreat before the remaining soldier. He stumbled over a corpse, cutting his calf on a sword as he fell, and rolled to avoid a two-handed blow from the soldier, scrabbling frantically in the ankle-deep mud for something, anything he could use as a weapon. A hilt brushed his fingers, and he ripped it from the muck and slashed at the soldier's sword hand, severing his thumb.

The man stared dumbly at the glistening stump, then said, "This is what comes from not shielding myself."

"Aye," agreed Roran, and beheaded him."

Eragon cried out, and in his desperation he reached for Saphira and the Eldunarí... and without meaning to, he drew from their stories of energy.
And with that energy he cast a spell.
It was a spell without words... His was a spell of instinct and emotion; language could not contain it.

Anger has its place, but it will not serve you here, the way of the warrior is the way of knowing. Of that knowledge requires you to use anger, then you use anger, but you cannot wrest forth knowledge by losing your temper.