This book is part of a two-part program focused on the broad theme of “biochemistry and fine-tuning.” Fitness of the Cosmos for Life began with a symposium held at Harvard University in October 20031 in honor of the 90th anniversary of the publication of Lawrence J. Henderson’s The Fitness of the The symposium was an interdisciplinary, exploratory research meeting of scientists and other scholars that served as a stimulus for the creative thinking process used in developing the content of this book. The chapters in this volume were developed following the symposium and take advantage of the rich technical and interdisciplinary exchange of ideas that occurred during.