He used data, evidence and statistics to drive change and make improvements. He admitted his mistakes and wrote and learned lessons in the hopes to prevent those mistakes from ever happening again.
However, a he was a man whose mistakes (with President Kennedy and Johnson) cost over a million lives.
Learning from mistakes and open criticism in a free society how societies grow for the betterment of all.
The NewsHour has two really great segments. First and interview with Robert McNamara and then a debate with John McCain, George McGovern and others about McNamara