Task: Determine the prevailing emotional tone of the tweet, categorizing it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that most accurately represent the tweeter's mental state.
Tweet: The word happiness would lose its meaning if it were not balanced by sadness.
This tweet contains emotions: 
anticipation, joy, optimism, sadness