Part life-coach, part Machiavelli, part Yoda, Balthasar Gracian [1601-1658], a Jesuit priest, wrote this collection of pithy sayings four centuries ago. Gracian speaks to the twenty-first century as well as the seventeenth. It's only a matter of time before someone markets Gracian's life advice to busy executives, like Sun Tzu or the Book of Five Rings (if it hasn't been already). In the meantime, Gracian can be our little secret.