Twenty-one scholarly assessments of the current state of man and the biosphere emanating from the annual winter lectures of the Institute of Contemporary Arts. The theoretical sections are intellectually demanding and laymen may find it difficult to follow some of the more specialized topics -- say, Raymond Vaissiere's paper on how cybernetics and information theory are helping biologists understand energy flows during ""24 Hours in the Life of a Rock-pool,"" or Mary Marples discussion of ""The Human Skin as an Ecosystem."" Biologist Hans Kalmus' paper on ""Living Together Without Man"" provides an invaluable detailed discussion of various modes of organic interaction -- commensalism, parasitism, predation, symbiosis, pollination and mimicry -- illustrating with hard scientific facts the infinite richness of interdependencies between plants, animals and their habitats. Two other contributors to the first section, Mary Douglas, a social anthropologist and Raymond Williams, the cultural historian, examine the progress of the idea of ""Nature"" through the centuries -- how it has been abstracted, personified, and all too often ""used as a verbal weapon of social control."" Part two, dealing with contemporary issues and controversies, is on the whole more accessible -- though the synoptic approach of most contributors will disappoint those looking for something new or provocative. Sewage disposal, wildlife conservation, food supplies, radiation, ocean resources and population control are discussed in separate articles with most writers agreeing that politics, not ""nature"" or ""science,"" is to blame for the present crisis. The consensus is that ""the scene need not be one of despair"" despite the soaring accretion of toxic fertilizer, chemical weaponry and inorganic waste. Michael Allaby asserts categorically that the food problem ""can be solved"" though the need to assert social control over presently anarchic production and distribution methods is urgent. A generally cautious and sanguine overview which repeatedly exhorts political action without offering any specific suggestions on how the politicos are to be persuaded -- or replaced.