The Jews did not get all this in its purity for various reasons. In the first place it was only gradually that the Jews became acquainted with the wealth of Aristotelian material. We are sure that Abraham Ibn Daud, the forerunner of Maimonides, had a thorough familiarity with the ideas of Aristotle; and those who came after him, for example Maimonides, Gersonides, Hasdai Crescas, show clearly that they were deep students of the ideas represented in the writings of the Stagirite. But there is not the same evidence in the earlier writings of Isaac Israeli, Saadia, Joseph Ibn Zaddik, Gabirol, Bahya Ibn Pakuda, Judah Halevi. They had picked up Aristotelian ideas and principles, but they had also absorbed ideas and concepts from other schools, Greek as well as Arabian, and unconsciously combined the two.
Another explanation for the rarity of the complete and unadulterated Aristotle among the Jewish thinkers of the middle ages is that people in those days were very uncritical in the matter of historical facts and relations. Historical and literary criticism was altogether unknown, and a number of works were ascribed to Aristotle which did not belong to him, and which were foreign in spirit to his mode of thinking. They emanated from a different school of thought with different presuppositions. I am referring to the treatise called the "Theology of Aristotle,"[6] and that known as the "Liber de Causis."[7] Both were attributed to Aristotle in the middle ages by Jews and Arabs alike, but it has been shown recently[8] that the former represents extracts from the works of Plotinus, the head of the Neo-Platonic school of philosophy, while the latter is derived from a treatise of Proclus, a Neo-Platonist of later date.
Finally a third reason for the phenomenon in question is that the Jews were the pupils of the Arabs and followed their lead in adapting Greek thought to their own intellectual and spiritual needs. It so happens therefore that even in the case of Abraham Ibn Daud, Maimonides and Gersonides, who were without doubt well versed in Aristotelian thought and entertained not merely admiration but reverence for the philosopher of Stagira, we notice that instead of reading the works of Aristotle himself, they preferred, or were obliged as the case may be, to go to the writings of Alfarabi, Avicenna and Averroes for their information on the views of the philosopher. In the case of Gersonides this is easily explained. It seems he could read neither Latin nor Arabic[9] and there was no Hebrew translation of the text of Aristotle. Averroes had taken in the fourteenth century the place of the Greek philosopher and instead of reading Aristotle all students read the works of the Commentator, as Averroes was called. Of course the very absence of a Hebrew translation of Aristotle's text proves that even among those who read Arabic the demand for the text of Aristotle was not great, and preference was shown for the works of the interpreters, compendists and commentators, like Alfarabi and Avicenna. And this helps us to understand why it is that Ibn Daud and Maimonides who not only read Arabic but wrote their philosophical works in Arabic showed the same preference for the secondhand Aristotle. One reason may have been the lack of historical and literary criticism spoken of above, and the other the difficulty of the Arabic translations of Aristotle. Aristotle is hard to translate into any language by reason of his peculiar technical terminology; and the difficulty was considerably enhanced by the fact that the Syriac in many cases stood between the original Greek and the Arabic, and in the second place by the great dissimilarity between the Semitic language and its Indo-European original. This may have made the copies of Aristotle's text rare, and gradually led to their disuse. The great authority which names like Alfarabi, Avicenna and Averroes acquired still further served to stamp them as the approved expositors of the Aristotelian doctrine.