On a scale of 1 to 7, how well did Ernest Shackleton demonstrate the principles of "Credibility is the Foundation of Leadership" from Kouzes and Posner's The Leadership Challenge? = very poor = poor = fair = good = very good = excellent = exceptional Which of the four essential characteristics of credibility (honest, competent, inspiring, forward-looking) did Ernest Shackleton use most effectively? Which of the four essential characteristics of credibility (honest, competent, inspiring, forward-looking) did Ernest Shackleton use least effectively