al-Baqillani

Abu Bakr Muhammad ibn al-Tayyib al-Baqillani (c. 338/950 – 403/1013) was a Sunni scholar of Iraq, a jurist of the Maliki madhhab (one of Sunni Islam's four schools of law) and a leading theologian of the Ash'ari school of kalam (rational or "speculative" theology). Later tradition called him a "second founder" of Ash'arism for the way he organised and defended its teaching.

He was born in Basra and spent most of his working life in Baghdad, then capital of the Abbasid caliphate, where he studied with pupils of the school's founder, al-Ash'ari, learned Maliki law, and taught. He is reported to have argued for the Qur'an's i'jaz — its "inimitability," the belief that its language could not be matched by human authors — and to have developed a rigorous occasionalist account of nature, in which God re-creates the world's atoms and accidents at every instant.

Al-Baqillani moved in the orbit of the Buyid ruler 'Adud al-Dawla, attending learned debates at the court in Shiraz. He is traditionally said to have been sent around 371/981 as an envoy to the Byzantine court at Constantinople, where biographical chronicles preserve colourful stories of his disputations with Christian scholars; the lively details are later tradition, though the embassy itself is widely reported. He served as a judge (qadi) and died in Baghdad. His surviving works include the theological manual Kitab al-Tamhid and a treatise on the Qur'an's inimitability. Whether he is best read as systematiser or innovator of Ash'arism is debated by modern scholars.