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: No pessimist ever discovered the secret of the stars,or sailed to an uncharted land,or opened a new doorway for the human spirit.-H.Keller
This tweet contains emotions: 
joy, optimism, pessimism