For several centuries now natural scientists have been occpupied with dissecting diverse forms of life into small components. Since Darwin the formation of diversity is subject to one basic principle: Competition. Theories on the meaning of natural selection and the survival of the fittest, on innate behaviour and instincts, on egoistic genes, on sexuality and choice of partner, battle of sexes miss one essential half. Scientists have forgotten to search for what keeps the living world, the single person, a couple, a group and last but not least the human community together: Love.