“Let me tell you the secret that has led me to my goal: my strength lies solely in my tenacityâ€
– Louis Pasteur (French Chemist and Microbiologist, 1822-1895)
Tenacity is a pretty fair substitute for bravery, and the best form of tenacity I know is expressed in a Danish fur trapper’s principle: “The next mile is the only one a person really has to make.”
 – Eric Sevareid