A book that does not mention this basic fact neither...

A book that does not mention this basic fact neither understand Shiaism nor Shia history. Even the doctrine of the Imamate may be said to be a 'corollary of the principle of basic importance of knowledge and justice. Justice, as defined by Imam ‘Ali (as) in the Nahj al-balaghah, is putting everything in its right place. Justice, in this sense, is action, and the most proper way of acting at that. Din, or Divine Law, since it relates to the right way of living, is included injustice.

Since one cannot act rightly without knowing what is the right thing to do in every case, justice is based on knowledge. The existence of an Imam is essential because he is, by virtue of his knowledge and his…