In the latter part of the fifteenth century, a Jewish translator, working together with a Slavic amanuensis, translated into the East Slavic language of the Grand Duchy of Lithuania three medieval Hebrew translations of Arabic philosophical texts: the Logical Terminology, a short work on logic attributed to Maimonides (but probably by a different medieval Jewish author); and two sections of the Muslim theologian Al-Ghazali's famous Intentions of the Philosophers. Highlighting the unexpected role played by Jewish translators as agents of cultural transmission in the heady messianic atmosphere leading up to the year 1492, these texts drew the attention of the Orthodox Church authorities as being in the possession of the enlightened heretical sect known as the Judaizers, which had emerged in Novgorod and spread to Moscow. Reflecting three and even four layers of translation, Prof. Moshe Taube's new triple-language critical edition of the Logika of the Judaizers displays the Slavic texts alongside the Hebrew translations on which they are based and accompanies them with a modern English translation. In his comprehensive introduction and commentary, Taube surveys earlier scholarly efforts to identify the provenance and purport of the translations, discusses the linguistic and textological issues raised by these early Ruthenian texts, puts forward the likely dissimilar motivations of the Jewish translator and the Christians who commissioned the work, and reveals the translator's probable identity. The present publication, a long-awaited desideratum, will be of interest not only to historians of the Great Duchy of Lithuania and of the principality of Muscovy, but also to scholars of Jewish history and of the history of philosophy and science, as well as to linguists studying the history of the Belorussian, Ukrainian and Russian languages.