[6][7] When Badajoz fell to the Almoravids in 1094,[8] Ibn al-Sīd went to Teruel in the territory of the Banū Razīn.
[3][5] In Zaragoza, sometime before 1110, he met the young philosopher Ibn Bājja, whom he debated on the role of logic in grammar.
[5] He wrote a fahrasa (an outline of his teachers and the works he studied under them) and commentaries on the Adab al-Kitāb of Ibn Qutayba, the Muwaṭṭaʾ of Mālik and the Saqṭ al-Zand of al-Maʿarrī.
He also wrote on theological differences within Islam in The Equitable Judgment on the Causes Originating Discrepancies in the Community (al-Inṣāf fī al-asbāb al-mūjiba li-khtilāf al-umma).
[3] Ibn al-Sīd was one of the earliest philosophers to explicitly seek to reconcile the Islamic religion with the "sciences of the ancients".
In the Book of Questions, he argues that philosophy and religion are two different means in pursuit of the same goal, the truth.
Ultimately derived from Neoplatonism and from the Neopythagorean Encyclopedia of the Brethren of Purity, partially through al-Fārābī, the metaphysical system of the Book of Circles is complex and eclectic.