 When we observe their lives as a whole, it must be noted that each had different strengths and weaknesses that caused them to succeed and fail in different areas of life. They had setbacks, they had failures, but they had one thing in common. These were men of perseverance. History records some of these men used their skills for great good, like a Joseph Lister, Eisenhower, or a Schweitzer. Others misused their genius to accomplish great harm, such as a Hitler, a Stalin, or a Mao.