I am very sorry to hear that one of my intellectual heroes, John David Lewis, has died following a long bout with cancer. He was a brilliant, passionate, and courageous advocate of reason and liberty. His loss strikes me on a personal level--our few encounters at Objectivist conferences demonstrated his warmth and intellectual honesty--but above all it is a blow to the defense of freedom and civilization.
Alex Epstein has a nice tribute, "Remembering John Lewis," on the CIP website. My wife wrote a post dedicated to him back in 2009.