The problem of pesticide-resistant mosquitoes is a variation on the same theme. Our only hope of "winning" is to recognize the truth in my definition of health -- a state of harmony. We must find ways to live in harmony with micro organisms and pests that we regard as our enemies. This means more new vaccines, and better understanding of the habits and habitats of pathogens and vectors, so we can stay out of each other's way, as we are beginning to try as one approach to malaria control, by better understanding of mosquitoes' habits. Ecological approaches, and mobilizing predators, where again mosquito control is a model of one way to do it, are other alternative tactics.