"Who can be wise, amazed, temperate and furious,
Loyal and neutral, in a moment? No man:
The expedition of my violent love
Outran the pauser reason. – Here lay Duncan,
His silver skin laced with his golden blood;
And his gashed stabs looked like a breach in nature
For ruin’s wasteful entrance: there, the murderers,
Steeped in the colours of their trade, their daggers
Unmannerly breached with gore. Who would refrain,
That had a heart to love, and in that heart
Courage, to make’s love known?"
He gives several reasons for killing the guards even though they would be the only witnesses to Duncan's death. List one.