“No creature can fly with just one wing. Gifted leadership occurs where heart and head – feeling and thought – meet. These are the two wings that allow a leader to soar.”
To me, Goleman is saying that no leader can lead with just smarts, but also with a passion for what they are doing. In other words, have the 'total package'. They must use knowledge and logic and be fully aware of their surroundings in order to be truly successful. Being a smart leader is equally important as being a passionate one and when one utilizes these traits they become a stronger, better, and matured leader.