Ja‘far al-Sadiqis believed to be the sixth infallible Imam, or spiritual leader, and successor to the Islamic prophet Muhammad. He is the founder of Shia fiqh, known as Ja'fari jurisprudence. He was an astronomer, an alchemist, an Islamic scholar and theologian, a writer,nbsp;a philosopher, a physician, and anbsp;physicist.Farhana Mayeris an editor in the Qur'anic studies unit at the Institute of Ismaili Studies in London. She is the coauthor of volume one of the IIS/OUP Tafsir Anthology series.