Among the extensive correspondence of Timothy I, Catholicos of the Church of the East, are two letters which refer to his collobaration in a translation of Aristotle's Topics into Syriac and Arabic, commissioned by the Caliph al-Mahdī. An annotated English translation of both letters is provided. Dans la volumineuse correspondance de Timothée I, Catholicos de l'Église orientale, deux lettres renvoient à sa collaboration à la traduction des Topiques d'Aristote en syriaque et en arabe, commandée par le Calife al-Mahdī. On trouvera (...) ici la traduction annotée en anglais de ces deux lettres. (shrink)