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.
Jacobs, the translator, is also the author of many books of folklore, etexts of which can also be found at this site, for instance, Celtic Fairy Tales, English Fairy Tales, and Indian Fairy Tales.
Production note: I have arbitrarily divided the body of the translation into files of 50 sayings each: Jacobs recommended reading the book 50 sayings at a time.