"Do you want to make a lot of money or do you want to work for justice? Do you want to run marathons or sing in a choir? Do you want to have children or travel the world? The things we care about in life - families, friendships, jobs, health, moral ideals, hobbies - tend to conflict with each other. Unresolvable conflicts make our lives worse, because they prevent us from doing what matters to us. Worse still, we don't always know what we really want,...