Curiously enough, in opposition to the Talmud and all later rabbinical tradition, he counts Daniel among the prophets, coinciding therein—but therein only—with the current Christian interpretation. He is impelled to this by the fact that Daniel furnishes the foundation for his Messianic theory. The remainder of his commentary is devoted to an exhaustive and caustic criticism of the Christian exposition. The second work is probably unique in being an exposition of the doctrine concerning the Messiah according to the traditional testimony of Talmud and Midrash. His third apologetic work contains a collection of Messianic passages of the Bible and their interpretations, in the course of which Abarbanel criticizes the Christian interpretation of these passages. Other works by Abarbanel include:  Ironically, according to David Brion Davis, a Yale historian who specializes in slavery, Abarbanel played a pivotal role in providing the conceptual basis for black slavery: "[...] the great Jewish philosopher and statesman Isaac ben Abravanel , having seen many black slaves both in his native Portugal and in Spain, merged Aristotle's theory of natural slaves with the belief that the biblical Noah had cursed and condemned to slavery both his son Ham and his young grandson Canaan. Abravanel concluded that the servitude of animalistic black Africans should be perpetual." Abarbanel's view on slavery, however, stood in direct contradiction to that of Rashi, who, citing an earlier Talmudic source, wrote that the heathen were never included in the sanction of possessing slaves as the children of Israel were permitted to do, for the Scripture says (Leviticus 25:44): "Of them "you" shall buy, etc.", meaning, "Israel alone is permitted to buy from them [enslaved persons], but they are not permitted to buy [enslaved persons] from you, nor from one another." Scholars including Jonathan Schorsch and David M. Goldenberg point out Abarbanel's comments on the Book of Amos as indicating very humanistic sentiments: "[Abarbanel] responded with unconcealed anger to the comment of a tenth-century Karaite from Jerusalem, Yefet b. Ali, on the issue of Black [promiscuity]. Yefet had interpreted a biblical verse (Amos 9:7) to refer to Black women as being 'promiscuous and therefore no one knows who his father is.' Abarbanel: 'I don't know who told Yefet this practice of promiscuity among Black women, which he mentions.