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: Friedrich Arnold was professor emeritus of anatomy and physiology at Heidelberg. He read medicine at the University of Heidelberg at the same time as his elder brother, Johann Wilhelm Arnold.
