Divine knowledge, especially that concerning the conditions of the next world and matters that logic cannot understand independently through speculative investigation, requires drawing light from the niche of the prophecy of the seal of the prophets (peace and blessings be upon him and his family), through the mediation of the first of his successors and the noblest of the saints of his community. For the lights of divine knowledge have spread in the souls of those who are ready to receive them from the full moon of his authority and the star of his guidance. This is clarified in the statement of the prophets (peace and blessings be upon him and his family): "I am the city of knowledge, and on me is its hair." In relation to the other saints and scholars, his holy man occupies the position of spiritual fatherhood, just as Adam, the father of the human race, occupies this position in physical birth. Therefore, the Prophet is reported to have said about him and his family: "O Ali, you and I are the fathers of this community." Mulla Sadra, The Secrets of the Verses, p. 229.