The work and thought leading to this book have spread over many years, and my debts go back to include all that were acknowledged in the preface to my previous book, Steps to an Ecology of Mind. But I have tried to write to be understandable to those who have not read Steps and therefore shall acknowledge here only debts contracted since Steps was published. Similarly, in the last stages of writing the book and following severe medical adventures, Esalen Institute took me in as guest, permitting me to combine writing with convalenscence. I have to thank Janet Laderman, Julian Silverman, Michael Murphy, Richard Price, and many others. Both at Esalen and at Lindisfarne, my debt is really to the total community.