There are several ways by which to approach the question of the authenticity of Zera Yacub's work. One is philological, by careful attention to the linguistic hints in the manuscripts that the work is not by a native writer of Ge'ez, or that otherwise suggest a later invention or conscious fabrication. Another is so to speak psychobiographical, by close attention to the character of Giusto d'Urbino, particularly as revealed in his correspondence from Ethiopia with the Parisian manuscript collector Antoine d'Abbadie. In a series of articles, Anaïs Wion has compellingly adopted both of these approaches. Less developed in her work is the approach informed by the history of philosophy, to wit: are there Latinate philosophical concepts in Zera Yacub's work, the circulation of which in 17th-century Ethiopia we might have reason to doubt? If there are, three possibilities present themselves. One is that, in spite of our surprise in finding them there, networks of circulation, likely headed up by Portuguese Jesuits, can be discovered that account for their presence. A second possibility is that the appearance of these terms is in part a consequence of lexical choices made by the first translators of the work and adopted in later scholarship. A comparative study of the two most significant translations of the Hatata, B. A. Turaev's Russian translation of 1904 and Enno Littmann's Latin translation of the same year, shows that both authors interpolate terminology that almost certainly comes from their own philosophical educations based on distinctly 19th-century curricula (e.g., Turaev's use of свет разума [“light of reason”] for a Ge'ez term that could be rendered otherwise with far less distinctly Cartesian resonance). A third possibility is that we can account for the presence of these concepts neither as signs of the inclusion of Ethiopia within the broader early modern connected history of Latinate philosophical ideas, nor as artifacts of the translational and scholarly traditions in which Zera Yacub was taken up, but rather as evidence that the work was in fact produced in the 19th century by a learned and deceptive Italian.