Classify the emotions found in the tweet "“The #greatest fear #dogs know is the #fear that you will not come back when you go out the #door #without them.”   \n  ―#Stanley #Coren". Select from the following: anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust. If the tweet is emotionless, reply "neutral or no emotion".
fear