There is some difference in the approach of a biographer and a historian. A biography is usually an exercise in hero worship. A biographer is prone to paint the picture of his hero in bright colors. The approach of a historian is basically objective and constructively critical. Every hero of a biographer may not necessarily be a great man from the point of view of history. Where the hero is a great man in history, his biography has to be projected in the context of history. Ali is verily a great man of the history of mankind in general and history of Islam in particular. In undertaking this study in the life of Ali, I have to act not merely as a biographer but as a historian as well. This means that besides narrating the main events in the life of Ali, I have to examine the impact of such events on history. As such I have to subject the main events in the life story of Ali to critical examination to ascertain their causes and effects. Of course such criticism has to be constructive.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari