Abner of Burgos

Abner of Burgos (c. 1270 – c. 1347, or a little later) was a Jewish philosopher, a convert to Christianity and polemical writer against his former religion. Known after his conversion as Alfonso of Valladolid.


As a student he acquired a certain mastery in Biblical and Talmudical studies, to which he added an intimate acquaintance with Peripatetic philosophy and astrology. He was graduated as a physician at 25, but throughout a long life he seems to have found the struggle for existence a hard one. In 1295, he reportedly treated a number of Jews for distress following their experiences in the failed messianic movement in Avila. As Abner reports in his Moreh Zedek/Mostrador de justicia, he himself "had a dream" in which a similar experience of crosses mysteriously appearing on his garments drove him to question his ancestral faith.[1]

Not being of those contented ones who, as Moses Narboni says in his Maamar ha-Beḥirah (Essay on the Freedom of the Will; quoted by Grätz, p. 488), are satisfied with a peck of locust beans from one Friday to another, he resolved to embrace Christianity though at the advanced age of sixty, according to Pablo de Santa María (Scrutinium Scripturarum); according to other writers he took this step soon after he was graduated in medicine. According to the statements of his contemporaries, such as Narboni, he converted, not from spiritual conviction, but for the sake of temporal advantage. Something of the apostate's pricking conscience seems to have remained with him, however, although he was immediately rewarded with a sacristan's post in the prominent Metropolitan Church in Valladolid (whence he took the name of Alfonso of Valladolid). The argument that Abner converted for material gain is put into question by the fact that his post as a sacristan was extremely modest and he never, throughout his long and public polemical career after conversion (c. 1320-1347) advanced in his post to something more lucrative.


Abner's most distinguishing characteristic was his use of postbiblical literature, including hundreds of Talmudic and Midrashic sources as well as much medieval Jewish and Arabic (in translation) literature, all in an effort to prove the truth of Christianity. Equally striking is the fact that he wrote his anti-Judaism polemics in Hebrew, unlike virtually every polemicist in the history of Christianity. His most major work, the Moreh Zedek (Teacher of Righteousness), which now survives only in a 14th-century Castilian translation as Mostrador de Justicia, is one of the longest and most elaborate polemics against Judaism ever written and is one of the key sources for the history of anti-Jewish thought in thirteenth and fourteenth century Western Europe. Abner's text rivals (and in many ways surpasses) the Pugio Fidei in length, complexity, variety of sources, and psychological impact, although there is no evidence that Abner actually knew of the polemical Dominican work.

In an essay entitled Minhat Qenaot (A Jealousy Offering), he argued that man's actions are determined by planetary influence, and he reinterpreted the notion of choice and free will in light of that determinism. Both his conversion and this defense of determinism aroused protests from his Jewish former study-partner, Isaac Pulgar, marked by great bitterness. Abner also exchanged a number of polemical letters with local Jews, which have survived along with the responses by each and the final riposte to all the letters by Abner, a short work known as the Teshuvot ha-Meshubot.

Abner presented charges before Alfonso XI of Castile, accusing his former brethren of using a prayer-formula in their ritual which blasphemed the Christian God and cursed all Christians. The king ordered a public investigation at Valladolid, in which the representatives of the Jewish community were confronted with Abner. The conclusion was announced in the shape of a royal edict forbidding the use of the formula in question (February, 1336); a barren victory on both sides, for the Jews had no idea of ever using it, and Abner failed to prove that they had. He further accused the Jews, for instance, of constantly warring among themselves and splitting into hostile religious schisms; in support of this statement he adduces an alleged list of the "sects" prevailing among them: Sadducees, Samaritans, and other extinct division. He makes two "sects" of Pharisees and Rabbinites, says that cabalists believe in a tenfold God, and speaks of a brand-new "sect" believing in a dual Deity, God and Metatron.


The following is a list of Abner's writings:

  1. The Moreh Zedek (Teacher of Righteousness), surviving only as the Mostrador de justicia (Paris BN MS Esp. 43, consisting of a dialogue containing ten chapters of discussions between a religious teacher (Abner?) and a Jewish controversialist.
  2. Teshuvot la-Meharef (Response to the Blasphemer), also in Castilian translation, Respuestas al blasfemo (Rome. Biblioteca Apostolica Vaticana MS 6423)
  3. Polemical letters and the Teshuvot ha-Meshubot.
  4. The Libro de la ley
  5. The determinist philosophical work Minhat Qenaot (Offering of Zeal), surviving only in Castilian translation as Ofrenda de Zelos or Libro del Zelo de Dios (Rome. Biblioteca Apostolica Vaticana MS 6423)
  6. A Mathematical treatise Meyyasher Aqob (Straightening the Curve)

Some of his lost works may include:

  1. A supercommentary on Ibn Ezra's commentary on the Decalogue, written before his apostasy.
  2. ''Sefer Milhamot Adonai ("Wars of the Lord"). This too was translated into Spanish, by request of the Infanta Doña Blanca, prioress of a convent in Burgos, under the similar title "Las Batallas de Dios."
  3. La Concordia de las Leyes, an attempt to provide Old Testament foundations for Christian dogmas. According to Reinhardt and Santiago (p. 86, n. 10.4) this text is found in Paris BN MS Esp. 43.
  4. Iggeret ha-Gezerah (Epistle on Fate).

Some of the works falsely attributed to him include:

  1. Libro de las tres gracias, Madrid Biblioteca Nacional MS 9302 (Kayserling). The title is a misreading of Libro de las tres creencias. According to Reinhardt and Santiago (pp. 86–88, n. 10.5) the text is also found in Escorial MSS h.III.3 and P.III.21, where it is called the Libro declarante.
  2. Libro de las hadas (also attributed to the Pseudo-San Pedro Pascual). According to Reinhardt and Santiago (p. 88, n. 10.6) this text is also found in Escorial MSS h.III.3 and P.III.21
  3. Sermones a los moros y judios. Found as anonymous in Soria: Casa de la Cultura, MS 25-H (Reinhardt and Santiago, p. 314, n. 143.6)
  4. The Epistola Rabbi Samualis and Disputatio Abutalib of Alfonsus Bonihiminis.

See alsoEdit


  1. ^ Ryan Szpiech, Conversion and Narrative: Reading and Religious Authority in Medieval Polemic (Philadelphia: University of Pennsylvania Press, 2013, chapter 5, pp. 143–73


  • Abner of Burgos/Alfonso of Valladolid. Meyyasher Aqob. Ed. G. M. Gluskina. Moscow, 1983.
  • ---. Mostrador de Justicia. Ed. Walter Mettmann. 2 vols. Abhandlungen der Nordrhein-Westfälischen Akademie der Wissenschaften, vol 92/1-2. Opladen: Westdeutscher Verlag, 1994; 1996.
  • ---. Teshuvot la-Meharef. In "The Polemical Exchange between Isaac Pollegar and Abner of Burgos/Alfonso of Valladolid according to Parma MS 2440 'Iggeret Teshuvat Apikoros' and 'Teshuvot la-Meharef'.” Ed. and Trans. Jonathan Hecht. Diss. New York University, 1993.
  • ---. Těshuvot la-Měharef. Spanische Fassung. Ed. Walter Mettmann. Abhandlungen der Nordrhein-Westfälischen Akademie der Wissenschaften, vol 101. Opladen: Westdeutscher Verlag, 1998.
  • Gershenzon, Shoshanna. "A Study of Teshuvot la-meharef by Abner of Burgos." Diss. Jewish Theological Seminary of New York, 1984.
  • Heinrich Grätz, Gesch. d. Juden, 3rd ed., vii.289-293.
  • Meyer Kayserling, Biblioteca Esp.-Port. Judaica, p. 114.
  • Loeb, "La Controverse Religieuse," in Rev. de l'Histoire des Religions, xviii.142, and in "Polémistes Chrétiens et Juifs," in Rev. Ét. Juives, xviii.52.
  • Reinhardt, Klaus, and Horacio Santiago-Otero. Biblioteca bíblica ibérica medieval. Madrid: Consejo Superior de Investigaciones Científicas, 1986.
  • Sainz de la Maza Vicioso, Carlos. "Alfonso de Valladolid: Edición y estudio del manuscrito lat. 6423 de la Biblioteca Apostólica Vaticana." Diss. U. Complutense, 1990. Madrid: Editorial de la Universidad Complutense de Madrid, Servicio de Reprografía, 1990.
  • Szpiech, Ryan. Conversion and Narrative: Reading and Religious Authority in Medieval Polemic. Philadelphia: University of Pennsylvania Press, 2013.

---. "From Testimonia to Testimony: Thirteenth-Century Anti-Jewish Polemic and the Moreh Zedek/Mostrador de justicia of Abner of Burgos/ Alfonso of Valladolid." Diss. Yale University, 2006.

External linksEdit

  • Ryan Szpiech, "From Testimonia to Testimony: Thirteenth-Century Anti-Jewish Polemic and the Mostrador de justicia of Abner of Burgos/Alfonso of Valladolid."
  • Ryan Szpiech, Conversion and Narrative: Reading and Religious Authority in Medieval Polemic.
  • Sadik, Shalom. "Abner of Burgos". In Zalta, Edward N. (ed.). Stanford Encyclopedia of Philosophy.