Ecological problems are explored in this book of sixteen student readings and exercises aimed at developing and applying critical thinking skills. The readings, mostly extracts from books and periodicals, are introduced by the editor and accompanied by questions. Chapter I, The Population Controversy, includes selections from Paul Ehrlich's The Population Bomb, and Pope Paul VI's Encyclical on Birth Control. Chapter II, The Nuclear Radiation Controversy, includes a case study involving litigation by a state against the Atomic Energy Commission. Chapter III, The Air Pollution Controversy, includes articles from Nation's Business, a U. S. Chamber of Commerce publication, The Progressive, and a publication of the Inter-Industry Emission Control Program. Chapter IV, The Religious, Political and Economic Consequences of the Ecology Controversy, includes selections from several university professors. A list of sources for more ecological information is appended. Related documents of interest are: SO 001 466, SO 001 467, and SO 001 469. (Auth/DJB)