SAMAU'AL BEN JUDAH IBN 'ABBĀS AL-MAGHRIBĪ, convert to Islam, mathematician, physician, and author of an anti-Jewish manual. He converted to Islam in 1163 and died ca. 1170. He left a polemical attack on the Jews and on Judaism, composed following his conversion, as well as an autobiographical account of his conversion, besides other works on scientific, especially mathematical, subjects. The name "al-Maghribī" indicates a connection with the Islamic west, and he may have been born there, but he spent most of his life in the east, converting to Islam in the city of Maragha (now in Azerbaijan). The son of a well-known father (Judah b. 'Abbās was a poet and a friend of *Judah Halevi), Samau'al refrained from converting for a long time out of respect for his father, but he eventually became a Muslim shortly before his father's death.
The reasons behind his conversion were of two kinds. The Prophet *Muhammad appeared to him in a dream, which he recounts in his work. However, while dreams are known quite often to lead to conversion, Samau'al did not accept religious experience as a legitimate argument for conversion. Only rational argument was acceptable to him. Thus, in his autobiography he describes his conversion as the product of a process of study and intellectual analysis which took place over a considerable period of time (an exchange of letters with an anonymous correspondent, published together with the autobiography, attempting to justify the conversion, wears the appearance of a literary construct).
Samau'al's main surviving work is his Ifḥām al-Yahud (Silencing the Jews). In this work Samau'al claims that the Bible is merely an invention by Ezra, that its transmission was unreliable, and that it cannot be regarded as authentic divine revelation. Nonetheless, like many a polemicist before and after (e.g., *'Abd al-Ḥaqq al-Islāmī), Samau'al is prepared to recognize the biblical text as authentic when it suits his case: he identifies several examples of biblical texts prophesying the advent of Muhammad (in particular Gen. 17:20 and Deut. 18:15–18) and uses gematria to show that Muhammad is referred to in the Bible (in the phrase bi-me'od me'od, Gen. 17:20, referring to the descendants of Ishmael, the sum of the numerical values of the letters of the Hebrew words equals the sum of the values of the letters in the name "Muhammad"). Above all, though, Samau'al claims that Judaism is to be rejected because the same arguments that can be made for Moses can also be
The argument of the equivalence of faiths might have led to atheism or to retention of Judaism, but Samau'al uses it to justify acceptance of Islam, on the ground that that faith includes all of the faiths that have preceded it. Acceptance of the faith of the majority thus has an intellectually respectable, as well as a socially pragmatic, aspect.
Samau'al's conversion was one of several at the time: besides Samau'al, we know also of the doctor and philosopher Abū al-Barakāt Ḥibbat Allāh, who converted at the end of his life, and of Isaac the son of Abraham b. Ezra. As all three were acquainted, there have been suggestions that Ḥibbat Allāh may have acted to influence the other two to convert, or that all these converts were part of a circle of intellectuals with shared interests and paths to Islam, but Stroumsa argues persuasively that this supposition is unfounded and that the conversions were independent.
M. Perlmann (ed. and trans.), Samau'al al-Maghribī, Ifḥam al-Yahūd Silencing the Jews (= Proceedings of the American Academy for Jewish Research, vol. 32) (1964); F. Rosenthal, "Al-Asturlabi and as-Samaw'al on Scientific Progress," in: Osiris, 9 (1950), 555–64; H. Lazarus-Yafeh, Intertwined Worlds. Medieval Islam and Bible Criticism (1992), index; S. Stroumsa, "On Jewish Intellectuals Who Converted in the Early Middle Ages," in: The Jews of Medieval Islam (1995), 179–97.