Each age has its "great work" according to Berry. The classical period introduced ideas of reason, democracy and philosophy into human consciousness. The medieval period raised great cathedrals, the age of discovery opened lines of travel and communication around the world, but our technological power and its impact on the environment has made a new "great work" essential for the human species.

Thomas Berry proposes that we are entering the "Ecozoic Age" where we must reestablish our connection to nature and work toward sustainable lifestyles that reverse the destruction we are currently inflicting on the planet. The Cenozoic Age with its flourishing of myriad life forms has passed into the spreading devastation of habitat, species extinction that accompanies our human technological monoculture. He traces the development of the attitude of domination and exploitation that has emerged and identifies the key areas in which a fundamental change in perspective is required. "We must learn that we are a communion of subjects, not a collection of objects".

He suggests that "other than human" interests must be given legal status and the corporate "entities" created under charter and law be limited to ethically responsible activities. He describes efforts to embody these new perspectives in our evolving culture. We need to have a rethinking of how humanity lives and acts individually and collectively in relation to the fragile ecosystem of the Earth.

He details where starts have been made and gives credit to people whose vision introduced us to the ecological outlook that an "ecozoic age" requires. He looks specifically at the role universities, governments, economics and religions can play in making the transition into a sustainable future. He suggests that we call upon the wisdom of indigenous people, the wisdom of women, the wisdom of classical literature and the wisdom of science. He describes how indigenous cultures evolved close relationships to the cycles of nature and produced a sense of the sacred interrelationships between living things. By suppressing these views European colonists missed the opportunity to learn how to move with the flow of natural process rather than dam, plow, and pave them into submission.

Women have also sensed the rhythms and cycles of nature and the connections that create community. Listening to and valuing this wisdom will be part of the "great work." Classical literature has preserved the evolving worldview of the great spiritual traditions and an understanding of their insights for the next phase of human development may be essential. Much of the cultural wisdom he identifies has been neglected or distorted to fit the ethos of power and domination that marked the industrial revolution.

Finally Berry continues the theme that he and Brian Swimme have been developing in earlier works that science is telling us a "new" story about the world that began with the "great unfolding" which sounds less fragmenting and more creative than a "big bang". That primal energy continues unfolding in the creative evolving complexity of the expanding cosmos. Thomas Berry is lyric in his description of the possibilities of reconnecting human aspirations to the organic processes of nature and the great whirling drama of the cosmos. He is realistic in his appraisal of the damage we are doing to other life forms in our current blindness but also optimistic that the "wisdoms" will lead us into the great work of understanding our place in the scheme of things and creating a sustainable future for ourselves and all that we are connected to.

Thomas Berry has become one of the great planetary "elders" of the environmental movement and one of the hopeful voices that says we can find our way through this difficult period of transition. He shows where important beginnings have already been made and points in the direction of a new age in which the insights of the past can be consolidated into a future for our children and for the other sentient beings with which we share this fertile, fragile yet immensely creative corner of the cosmos. It is a "great work".