Opus Majus of Roger Bacon, Vol. II (Burke English trans.)

CHAPTER V

An exposition of authorities at variance regarding the faculties mentioned.

BUT the Latin text of Aristotle does not disclose to us this division, for there is no express mention made except in regard to the common sense, imagination, and memory. But since the text of Aristotle, owing to faulty translation, cannot be understood in this part of his work, and the same difficulty is found in other passages; and since Avicenna was the perfect imitator and expositor of Aristotle in nearly every respect, and was the greatest philosopher subsequent to him, as the Commentator Averroes states in the chapter on the Rainbow, we must for this reason hold to the opinion of Avicenna, which is clear and perfect. This is true although the translators of the works of Avicenna—as in his book On the Soul, and in that On Animals, and in his books on Medicine—have translated differently and have changed words, so that Avicenna's meaning has not been translated to the same purport throughout. In his book On Animals we find that the estimative faculty takes the place of reason in brutes, and so too we sometimes find elsewhere contradiction with respect to the aforesaid matters; but the fact is of little moment that different translators use different words, and sometimes in part of a subject show some diversity. But we must hold to his view as expressed in his book On the Soul, because he there discusses the faculties of the soul as his principal topic, whereas elsewhere his mention of this subject is rather incidental. Moreover, that work has been translated far better than his other books, a fact that is evident since it has few or no words belonging to other tongues, while his other books have them in countless numbers. If one really considers what has been said above, he must assume that there are three faculties wholly different, according to the three cells. For a diversity of objects shows us a diversity of faculties. For there are two kinds of properties: one external, as the twenty-nine mentioned above, the other internal, hidden from external sense, as the quality of a harmful or useful complexion, or rather the essential nature itself, whether useful or harmful.