Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Not by wrath does one kill, but by laughter.  Friedrich Nietzsche #friedrichnietzsche
This tweet contains emotions: 
joy