سِيرَةُ الأَشعَرِيّ — أَبو الحَسَنِ الأَشعَرِيُّ [260-324هـ / 874-936م]: المُتَكَلِّمُ الَّذِي أَسَّسَ عِلمَ الكَلَامِ الأَشعَرِيَّ بِالانفِصَالِ عَن شَيخِهِ المُعتَزِلِيِّ الجُبَّائِيِّ لِلدِّفَاعِ عَن العَقِيدَةِ السُّنِّيَّةِ التَّقلِيدِيَّةِ بِالمَنَاهِجِ العَقلِيَّةِ مُؤَسِّسًا المَذهَبَ السَّائِدَ فِي عِلمِ الكَلَامِ السُّنِّيِّ الَّذِي لَا يَزَالُ يُهَيكِلُ التَّعلِيمَ الدِّينِيَّ الإِسلَامِيَّ فِي العَالَم
Seerah al-Ashari (سِيرَةُ الأَشعَرِيّ; full name: Abu al-Hasan 'Ali ibn Isma'il al-Ashari; born 260 AH / 874 CE in Basra; died 324 AH / 936 CE [some sources give 935 or 935-936 CE]; a Shafi'i scholar in fiqh but the founder of a new school in kalam [speculative theology]; his teacher: al-Jubbai [Abu 'Ali Muhammad ibn 'Abd al-Wahhab al-Jubbai, d. 916 CE], the leading Mu'tazili theologian of his day; al-Ashari studied with al-Jubbai for approximately 40 years; the famous break: the classical accounts describe the break as triggered by a debate about divine justice and the question of three brothers — one died as a believer, one as an unbeliever, one as a child; al-Jubbai's answers to the child's case created difficulties in his system of divine justice [the child might complain: 'Why did God let me die before I could earn reward?']; al-Jubbai's responses became internally inconsistent; al-Ashari reportedly said: 'You have blocked me' and broke from Mu'tazilism; the reliability of this account is debated by modern scholars; what is clear is that al-Ashari made a public break from Mu'tazilism in Basra around 912-913 CE; the public announcement in the mosque: in the famous account, al-Ashari mounted the pulpit and publicly declared his break from Mu'tazilism, announcing that he would defend the traditional Sunni doctrines using rational methods; this theatrical gesture signaled that the break was complete and public; al-Ashari's position: he maintained [1] that the Quran is the uncreated speech of God [against the Mu'tazili position that the Quran is created]; [2] that God's attributes [knowledge, power, will, etc.] are real and distinct from His essence [against both the Mu'tazili position that they are identical with the essence and the anthropomorphist position that they are literal]; [3] that God's acts are not constrained by human rational standards of justice [against the Mu'tazili position that God is rationally obligated to do what is best for humans]; [4] that human acts are 'acquired' [kasb/iktisab] by humans but created by God [the doctrine of kasb — a middle position between Mu'tazili free will and Jabriyya determinism]; major works: [1] al-Ibana 'an Usul al-Diyana [The Elucidation of the Foundations of Religion]: a short work defending the traditional Sunni position, particularly attributing al-Ashari to the school of Ahmad ibn Hanbal; scholars debate whether this represents al-Ashari's mature position or an early period; [2] al-Luma' fi al-Radd 'ala Ahl al-Zaygh wal-Bida' [The Highlights in Response to the People of Deviation and Innovation]: a more detailed rational-theological work; [3] Maqalat al-Islamiyyin [Positions of the Islamic Schools]: a comprehensive survey of different Muslim theological positions — one of the earliest works of comparative Islamic theology; the Ash'ari school after al-Ashari: his students and their students developed Ash'ari kalam: al-Baqillani [d. 1013 CE] systematized the position on i'jaz; al-Juwayni [d. 1085 CE] refined the kalam methods; al-Ghazali [d. 1111 CE] synthesized Ash'ari kalam with Sufi practice and legal knowledge; the Ash'ari school became dominant in Shafi'i and Maliki contexts; the Hanbali school remained resistant; the parallel development: in Transoxiana, Abu Mansur al-Maturidi [d. 944 CE] developed a parallel kalam school within the Hanafi tradition; Ash'ari and Maturidi became the two orthodox Sunni kalam schools) is Sunni Islam's most influential theologian.
Forty Years with the Mu’tazila
Al-Ashari did not come to Ash’ari kalam from nowhere. He spent approximately forty years studying with al-Jubbai, the leading Mu’tazili theologian of his time. He learned the methods of rational theological argument — the tools that would eventually make Ash’ari kalam a coherent system — from within the tradition he would eventually publicly renounce.
The famous story of the three brothers — believer, unbeliever, and child dying young — and the problems it created for Mu’tazili accounts of divine justice, may or may not be the actual trigger. What is clear is that al-Ashari concluded that Mu’tazili rationalism could not adequately account for certain core theological commitments: the uncreated Quran, real divine attributes, and genuine human responsibility for acts that God creates.
The Doctrine of Kasb
Al-Ashari’s most technically significant contribution to kalam was the doctrine of kasb (acquisition): human acts are created by God but acquired by humans in the moment of action. God creates the act; humans acquire it as theirs. This avoided both pure determinism (humans are automatons) and Mu’tazili free-willism (humans create their own acts, which limits divine omnipotence).
Whether kasb successfully threads this needle remains one of the most debated questions in Islamic philosophical theology. Critics argue it is determinism under a different name; defenders argue it preserves both divine omnipotence and human moral responsibility.
The School After the Founder
The Ash’ari school’s intellectual development accelerated after al-Ashari himself. Al-Baqillani, al-Juwayni, and above all al-Ghazali built on al-Ashari’s framework in ways that made it the dominant theological program in Shafi’i and Maliki education worldwide. The founder created the project; his successors made it a system.
See also: Seerah Al Ghazali, Seerah Al Juwayni, Seerah Al Maturidi, Fiqh Al Ijtihad Wal Taqlid, Fiqh Al Usul Al Fiqh