is something superadded to its quiddity; this is the view of Abū Hāshim and others among the Muʿtazilah who maintain that the non-existent is still a “thing,” and that its fixed reality (thubūt) is distinct from its actual existence (wujūd). Some who do not count the non-existent as a thing nevertheless followed them in separating existence from quiddity—such as Abū ʿAbd Allāh Ibn al-Khaṭīb and others who blended portions of Muʿtazilite discourse with that of the philosophers.
By contrast, the doctrine that the existence of every thing is identical with its very quiddity is the position of Ahl al-Sunnah wa-l-Jamāʿah and of all the other theologians who affirm the divine attributes, including Abū Muḥammad Ibn Kullāb (1), Abū al-Ḥasan al-Ashʿarī (2), Abū ʿAbd Allāh Muḥammad Ibn Karrām (3), and most of the later theologians, who side neither with the Muʿtazilah who say that the non-existent is a thing nor with the philosophers who claim that every existent possesses, in external reality, a quiddity separate from its existence.
(1) Abu Muhammad Abdullah ibn Said ibn Kullab (with a u-vowel on the kāf and a doubled lām), known as al-Qattan al-Basri, was the leading mutakallim (dialectical theologian) of Basra in his day and authored several refutations of the Muʿtazila. Among those who studied kalam with him were Dawud al-Zahiri, and some report that al-Harith al-Muhasibi also learned the disciplines of speculative theology and debate from him. His followers were called the Kullabiyya. Al-Dhahabi states that he was still alive shortly before 240/855. See: Siyar aʿlam al-nubalaʾ, 11:174; al-Aʿlam, 4:90.
(2) Ali ibn Ismail ibn Ishaq, Abu al-Hasan, a descendant of the Companion Abu Musa al-Ashari, was one of the foremost independent theologians. Born in Basra, he first embraced the Muʿtazilite school and excelled in it, then publicly broke with them. He died in Baghdad in 324/936. See: Siyar aʿlam al-nubalaʾ, 15:85; al-Aʿlam, 4:263.
(3) Muhammad ibn Karram ibn Iraq ibn Huzabah, Abu Abdallah al-Sijzi (from Sijistan), was the leader of the Karramiyya sect. Born in Sijistan, he resided in Mecca for five years, then visited Nishapur, moved on to greater Syria, returned to Nishapur, and left it in 251/865 for Jerusalem, where he died in 255/869. See: al-Milal wa-l-nihal, 1:108; al-Aʿlam, 7:14.