In any endeavor involving more than one person there is bound to be disagreement. How that disagreement is viewed and handled makes all the difference. Great leaders from Abraham Lincoln to Ray Dalio have known that disagreement is a good thing and have intentionally surrounded themselves with people of opposing viewpoints, as Doris Kearns Goodwin describes in Team of Rivals, her biography of Abraham Lincoln, and as Ray Dalio describes in his new book Principles about how he