“Three grand essentials to happiness in this life are: Something to do, something to love, and something to hope.” ~Joseph Addison, English poet and essayist There’s something to be said for “The Rule of Three” — a time-honored literary device. We’ve got those three blind mice, three musketeers, three spirits of Christmas, and three wise men, just for starters. And of course, in countless fairy tales, the protagonist is granted three wishes or given three tasks. Yesterday I posted a few thoughts on the benefits of Dr. Andrew Weil’s “Three Good Things” journaling exercise. Today, along these lines, 18th-century essayist Joseph Addison gives us “three grand essentials” for happiness. How…