Bustān al-ʿUqūl בֻּסְתַאן אַלְעֻקוּל

Written in Judaeo-Arabic around 1160; its Hebrew title is Gan ha-Sekhalim, "the Garden of the Intellects."

The book builds a Jewish doctrine of God, creation, the soul and prophecy in the conceptual language of Ismāʿīlī philosophy—the state theology of the Fatimids and living thought in the Yemen of that time. From this come its two most-discussed positions. First: prophecy proceeds in cycles, and to each nation in its turn a messenger is sent. Second, and consequent: Muḥammad was a genuine prophet sent to the Arabs—while the Torah is not abrogated for Israel and remains binding.

In medieval Jewish literature this is an almost solitary position. The usual Jewish move is either to deny Muḥammad's prophecy or to sidestep the question; al-Fayyūmī answers in the affirmative and builds the answer into a coherent system. The nearest parallels are sought not among Jewish authors but in Ismāʿīlī writing.

The book therefore belongs beside the Epistle to Yemen. Maimonides was writing to this author's son, into a community where such theology was native and respected—and his insistence on the cessation of prophecy and on the failure of the Muslim scriptural proofs is, among other things, an argument with the Bustān al-ʿUqūl. Two letters ten years apart are a conversation, not a monologue from centre to periphery.

Editions: English with translation by David Levine, Columbia University, 1908; Hebrew by Rabbi Yosef Qāfiḥ, Jerusalem, 1954.