(1) Abū Abd Allāh Muhammad ibn Abd Allāh ibn Tūmart al-Masmūdī al-Barbarī, known as al-Mahdī or Mahdī al-Muwahhidīn, founded the Almohad state upon the ruins of the Almoravid state. The year of his birth is disputed, but he died in 524 AH, aged between fifty-one and fifty-five. His works include *Aʿazz mā yutlab* (The Most Precious Object of Pursuit), published by Goldziher (Algiers, 1903); *Kanz al-ʿulūm* (The Treasury of the Sciences), which remains in manuscript; and *al-Murshida* (The Guide), a short treatise printed several times, most recently in *Nusūs falsafiyya muhdat ilā al-Duktūr Ibrāhīm Madkūr* (Philosophical Texts Dedicated to Dr. Ibrāhīm Madkūr; Cairo, 1967). On Ibn Tūmart’s life and doctrine, see Professor Abd Allāh Kannūn’s study in the aforementioned *Nusūs falsafiyya*, pp. 99–115; Yahyā Huwaydī, *Tārīkh falsafat al-Islām fī al-qārra al-Ifrīqiyya* (History of Islamic Philosophy on the African Continent), 1:223, 243; also *Wafayāt al-aʿyān*, 4:137, 146; Ibn al-Athīr, *al-Kāmil*, 10:201, 205; and *al-Aʿlām*, 7:104, 105. (2) The text between square brackets is omitted from manuscripts (N) and (M). (3) Manuscript (B) alone reads: “whereas the latter does not maintain [it].” This is an error. See also Ibn Taymiyya’s statement concerning Ibn Tūmart in *Darʾ taʿārud al-ʿaql wa-l-naql*: “Thus, the substance of his position agreed with that of Ibn Sabʿīn and others like him who affirmed absolute existence.” (4) Manuscripts (N) and (M): “vie with the others”; manuscript (A): “he vies with the followers of the others”; manuscript (B), using a feminine singular verb: “the followers vie with the followers of the others.” (5) Manuscript (A): “just as he had determined regarding…”; manuscript (B): “just as I had gathered among…”; manuscript (N): “just as [they] met with me.” (6) Manuscripts (N) and (M): “unless you disclose.” (7) “To us” is omitted from manuscripts (A) and (B).