Twenty-one years after publishing Wilderness and the American Mind, historian/conservationist Nash (U. Cal. at Santa Barbara) has written an absorbing account of the environmental movement(s) in America. Rugged individualism, our sense that vast open spaces were there to be exploited, and the need to settle the slavery issue first contributed to the lag in sensibility between the US and England with regard to an extension of ethical concerns to animals. We have now caught up and are witnessing an unprecedented era of activism ranging from violent sit-ins at lumber camps, laboratories, and nuclear test sites to the more benign rescue funds, humane societies, and traditional preservation groups. Why such a wide spectrum of activism? Because, says Nash, of the pluralism so characteristic of American society, which would lead to the liberating movements of the 60's and 70's: civil rights, women's rights, the peace movement, a new interest in Eastern mysticism, the birth of ""whole earth"" philosophies, the Gaia hypothesis, and pivotal books like Silent Spring. The violence is in character too, according to Nash, who argues that we are not able to reform society without civil disobedience. Nash sees a strong parallel between today's struggle for animal/plant/earth rights and the abolitionist movement that began decades before the Emancipation Proclamation. We may some day come to terms with ""biocentrism,"" but the majority of citizens do not surrender rights gladly. Excellent source material presented with overall sympathy for the advocates--which may offend those who deplore violence no matter what the end.