Among non-Shi‘ites, Ashari theologian Fakhr ad-Din ar-Razi is one of the supporters of the idea of the Ismah of the prophets. He stated his view is as follows: "According to us the best view is that, owing to their prophethood, there is neither a grave nor a small sin or error (dhanb)." Besides investigating the subject in his Commentary on the Qur'an, he wrote a separate book titled "Ismatu'l-Anbiya" ("The Sinlessness of the Prophets"), and championed the cause of this dogma being a part of Sunni theology. But Abū Hayyān al-Tawhīdī, a Sunni Philosopher, rejected this doctrine.