Henri Atlan is Professor of Biophysics at the University of Paris and Ishaiah Horowitz Hadassah Scholar in Residence for studies in Philosophy and Ethics of Biology at the Hadassah Hebrew University Medical Center in Jerusalem. He is a member of the French National Presidential Committee for Ethics of Life and Health Sciences.

This book is a thorough and critical, comparative analysis of the logic of modern scientific thought and of traditional teachings generally referred to as mythological and mystical.
Different rationalities with different domains of interest and legitimacy exist, which should not be confused and cannot be unified in any theory of "Ultimate Reality." Atlan suggests they must coexist in practice, although each of them presents itself as an exclusive and all-encompassing truth. The book introduces teachings from Jewish talmudic, midrashic, and kabbalist sources and text from Zen and Taoism to exemplify the kind of rationality or controlled irrationality at work in such traditional thinking.