A man who is morally clean, other things being equal, has in every instance, greater agility, greater capacity, and greater endurance by far than the man who is not. While the latter is wasting his creative energies in useless pleasures, as well as in disease producing habits, the former is turning all of his creative energy into ability and genius, and the result is evident.

Your Forces and how to Use Them (ed. Library of Alexandria, 1966) - ISBN: 9781465578563