"Knowing how we know" is the theme of this book. The authors present a new perspective on cognition that has important social and ethical implications, as they argue that the only world we humans can have is the one we collectively create through our interactions. The book is written for both a general audience and for students, scholars, and researchers, and is richly illustrated with examples from biology, linguistics, as well as new social and cultural phenomena. This revised edition includes a new afterword by Dr. Varela, in which he discusses the impact of the book in the years since its initial publication.