The complexity of this whole world syndrome can be overwhelming, yet to evade the complexity by taking the system apart to treat the problems one at a time can produce disasters. The great failings of scientifi c technology have come from posing problems in too small a way. Agricultural scientists who proposed the Green Revolution without taking pest evolution and insect ecology into account, and therefore expected that pesti-cides would control pests, have been surprised that pest problems increased with spraying. Similarly, antibiotics create new pathogens, economic development creates hunger, and fl ood control promotes fl oods. Problems have to be solved in their rich complexity; the study of complexity itself becomes an urgent practical as well as theoretical problem.These interests inform my political work: within the Left, my task has been to argue that our relations with the rest of nature cannot be separated from a global struggle for human liberation, while within the ecology movement my task had been to challenge the “harmony of nature” idealism of early environmentalism and to insist on identifying the social relations that led to the present dysfunction. On the other hand, my politics have determined my scientifi c ethics. I believe that all theories which promote, justify, or tolerate injustice are wrong.