Many critics repeatedly said Carson was calling for the elimination of all pesticides, but she had made it clear she was not advocating this but was instead encouraging responsible and carefully managed use with an awareness of the chemicals' impact on ecosystems. She concludes her section on DDT in "Silent Spring" with advice for spraying as little as possible to limit the development of resistance. Mark Hamilton Lytle writes, Carson "quite self-consciously decided to write a book calling into question the paradigm of scientific progress that defined postwar American culture".