The document discusses four theories about what leads to happiness: 1) Pursuing wealth, possessions and pleasure, 2) Taking care of one's physical and mental health, 3) Living sustainably and caring for the environment, and 4) Finding happiness through acts of kindness, giving, and caring for others rather than oneself. The key message is that true happiness comes from focusing outward by doing small kind acts for others each day rather than being self-focused.