Everyone knows what an emotion is.. until they are asked to explain it. We all have a sense that we are living emotional lives and that these emotional drives have immense control of our behavior but it’s hard to say what that emotion actually is. Is it the physiology? Is it the brain activity? Can single cells have feelings or emotions without nervous systems? Are there such things as basic emotions (happiness, fear, anger, surprise.. etc) and are there dedicated brain systems for them?