Well, now that I've finished it, here's a review!
One of the major themes that I took away from this book is the idea of "dissociation." Dissociation involves a fracturing of what Glendinning calls the "primal matrix": a condition of active interconnectedness with the the natural world which constitutes psychological wholeness and personal integrity. A Cartesian mind/body split is an example of a dissociated self; another example is a fragmented self-identity. Glendinning discusses the relatedness and similarities between post-traumatic stress and dissociation, and in doing so, she forges a link between personal healing and the healing of our relationship with the Earth.
In the first part of her book, Glendinning talks in detail about the psychological and social characteristics of nature-based people that serve to nurture a self that is engaged with the primal matrix. She also describes the historic process of civilization's dissociation from nature, beginning with the advent of agriculture and moving up to our present, mass technological society.
People who have experienced trauma enter into a state of dissociation (which can be mended, as Glendinning illustrates by telling of her own ongoing process of reconnecting with the primal matrix). But even people who have not experienced major psychological trauma are compelled to participate in our widely-dissociated and fractured society, and that also constitutes a form of oppression and denial. In our society, we are prevented from knowing, from a very early age, our true place and purpose, our real belonging, intertwined with the web of life.
In the latter section of the book, Glendinning proposes some solutions to this dilemma. She notes that a solution cannot take place on a merely individual psychological level; that it must involve interwoven restoration efforts on personal, social, and ecological scales.
I recommend this book-- it's a seminal work of eco-psychology, well-researched, on point, intelligently and poignantly written.