Doctor Samuel Landauer of the University of Strassburg published both the Arabic text, and his own concise German translation, of this Research into the Faculties of the Soul, in volume 29 for the year 1875 of the Z.d.D.M.G., together with his critical notes and exhaustively erudite confrontations of the original Arabic with many Greek passages from Plato, Aristotle, Alexander Aphrodisias, and others, that Ibn Sînâ had access to, it would appear, second hand, i.e. through translations. Doctor Landauer made use also of a very rare Latin translation by Andreas Alpagus, printed at Venice in 1546; and of the Cassel second edition of Jehuda Hallévy’s religious Dialogue entitled Khusari, which is in rabbinical Hebrew, and on pages 385 to 400 of which the views of “philosophers” on the Soul are set forth, Doctor Landauer having discovered to his agreeable surprise that those 15 pages are simply a word for word excerpt from this Research by Ibn Sînâ. For the Arabic text itself, he had at his command only two manuscript copies, the one, preserved in the Library at Leyden, being very faulty; and the other, in the Biblioteca Ambrosiana at Milan, being far more accurate and correct. This text was reprinted talis qualis, but with omission of every kind of note, in 1884 at Beirût, Syria, by Khalîl Sarkîs: this reprint is very hard to find. James Middleton MacDonald, M.A., made a studiedly literal English translation or rather a construe of it in 1884, of which he got a small number printed in pamphlet form at Beirût, and by Khalîl Sarkîs also: this English Version too is very rare, and almost unknown. * * * * * My present English rendering of this Essay by Avicena on the Powers of the Soul has been made directly and finally from the Arabic Original as given in the Landauer Text, with constant consultation however of both the Landauer German translation and the MacDonald English construe: it has been made not for European scholars and Arabists but solely for pupil students in Egypt, which circumstance called in a great measure for the use of two or more nearly synonymous words where the Arabic original often has but one only. Indeed I am not ashamed to say further that in some places I have failed to follow the drift and understand the purport of Ibn Sînâ’s argument; so that in such passages I am only too conscious of how far my rendering may perhaps have wandered from the right and true sense. But the author himself declares that psychology is one of the deepest and darkest of studies; and he relates of himself in his autobiography that he had read one of Aristotle’s writings forty times over, until he had got it by heart, and yet had failed to see the point. And he goes on to tell of how it was that he one day stumbled across and then read over al-Fârâbî’s “Maqâçid Aristotle,” whereupon mental light dawned upon him as to the purport of that writing.