Now, as Aquinas, with open book of heavenly doctrine, is figured in the chief position on the opposite (north) wall of the chapel, it is no unreasonable conjecture which finds in the magician’s book on the south wall a pictorial representation of the _Ars Notoria_ as it was conceived by Passavanti. Elsewhere in the volume he again returns to the subject of magical works.[296] Zoroaster, he says, first learned the art from demons, and caused it to be written on two columns, one of marble to survive the floods, and one of terra-cotta to resist the fire. This diabolic teaching, thus preserved, flourished among the Egyptians, Chaldeans, Persians, Indians, and other Oriental nations who remained its chief exponents, ‘though perchance,’ adds Passavanti, ‘it may be more studied among ourselves than we are ready to believe.’[297] This passage may serve to show why the artist of the Spanish Chapel was directed to draw his Magus in the fashion of the East, and helps us to understand the prejudice which Michael Scot’s outlandish costume must have raised against him. It is in any case certain that the stories of his supernatural power became both memorable in substance and rich in details by association with the tales of Arthur. CHAPTER X THE LEGEND OF MICHAEL SCOT—CONCLUSION The attachment of Michael Scot to his master, the Emperor Frederick II., may be conceived as acting in a double sense to procure him his mysterious fame. With the Guelfs, who bitterly opposed that great monarch and his followers, it of course became a reason for believing him to have practised the blackest of arts. With the Ghibellines, on the other hand, who formed the imperial party, and saw a very Arthur in their famous leader, it served to confirm his character as a Mage and man of mysterious might. Commencing then with one of the first, and certainly the most famous of the authors who have spoken of Scot in this romantic and legendary style, the observation just made will enable us to understand without much difficulty the sense of Dante’s reference to the magician. The poet represents himself as reaching the fourth division of the eighth infernal circle, when Virgil draws his attention to one of those who suffer there, and says: ‘Michele Scotto, fù, che veramente Delle magiche frode seppe il giuoco.’[298]