The Second Nature, the last and least technical of the author's books, represents the epitome of his thoughts regarding the function of the brain. In a synthesis of Philosophy, Psychology, Psychoanalysis, Evolutionary Biology, and Neuroscience, it lays the foundation for a Neurobiological Epistemology as a positive science.

At the basis of this foundation, one encounters classic and contemporary thinkers: Descartes, Darwin, Kant, William James, Piaget, Freud, Schrödinger, Popper, Chomsky, Turing, Sperry, Changeux, Damasio, Dawkins, Gould, Wilson, all parade in the author's narrative.

Edelman argues that the separation between the natural sciences and the humanities, as well as the different approaches to worldly issues by them, can be eliminated if one seeks their common roots in the function of the brain. He believes that there can be no comprehensive science if consciousness is not explained in biological terms.

The issue of human consciousness is at the center of his exploration. He bridges the study of phenomena from science ("third person") with the subjectivity of experience from the individual ("first person").

Thus, he distinguishes two interconnected "natures," the Nature of the outside world and the "second nature," which encompasses both human nature as a whole and the concept of spontaneous action.

As he notes in the preface: "This book was born out of my effort, systematic or otherwise, to understand what the discoveries of Neuroscience mean for the issues of human knowledge. The product of my thought regarding these specific issues is expressed in more lenient and heterogeneous terms than those of philosophers who are attached to traditional Epistemology. I believe this difference provides a useful starting point for further exploration of how we know. I encourage the reader to approach the book as an initial exploratory attempt that aims for a new thought regarding how we know the world and ourselves."

Author: Gerald M. Edelman (1929–2014) was a professor of Biochemistry at Rockefeller University and of Neurobiology at the Scripps Institute. He was awarded the Nobel Prize in Medicine in 1972 for the discovery of the molecular structure of antibodies. In the last decades of his life, he studied the neurobiological bases of consciousness and published, among others, the books Neural Darwinism (1987), Topobiology (1988), Bright Air, Brilliant Fire (1992), The Universe of Consciousness (2000), and Wider than the Sky (2004).