Knowledge of Life Today presents the thoughts of Jean Gayon, a major philosopher of science in France who is recognized across the Atlantic, especially for his work in philosophy and the history of life sciences. The book is structured around Gayon's personal answers to questions put forward by Victor Petit. This approach combines scientific rigor and risk-taking in answers that go back to the fundamentals of the subject.

As well as the relationship between philosophy and the history of science, Gayon discusses the main questions of the history and philosophy of biology that marked his intellectual journey: Darwin, evolutionary biology, genetics and molecular biology, human evolution, and various aspects of the relationship between biology and society in contemporary times (racism, eugenics, biotechnology, biomedicine, etc.).