Everyone confesses in the abstract that exertion which brings out all the powers of body and mind is the best thing for us all; but practically most people do all they can to get rid of it, and as a general rule nobody does much more than circumstances drive them to do.
Bio: Gregory Benford is an American science fiction author and astrophysicist who is on the faculty of the Department of Physics and Astronomy at the University of California, Irvine. He is also a contributing editor of Reason magazine.