Does the brain think? Is it the creator of the world of experience, the constructor of the subject? This widespread interpretation of the neurosciences is contrasted in this book with an ecological conception: The brain is above all an organ for mediating the relationships between the organism and the environment and for our relationships with other people. These interactions are constantly altering the brain, making it an organ that is biographically, socially and culturally shaped. In short, it is not the brain as such, but rather the living human being who feels, thinks and acts. In this sixth edition, the author presents a new updated version of his pioneering work, which was enthusiastically welcomed by specialists and the press.