This was the part of his work on which Bacon most prided himself, and in it, we may add, he seems to owe most to the Arab writers Kindi and Alhazen.
Vitello's work is to a very great extent based upon Alhazen and some of the earlier writers, and was first published in 53 5.
Alhazen, quoted by Purchas in his quaint notice of Timur and referred to by Sir John Malcolm, can hardly be accepted as a serious authority.
But, although the existence of this Alhazen of Jean de Bec has been believed by many, the more trustworthy critics consider the history and historian to be equally fictitious.
He is to be distinguished from another Alhazen who translated Ptolemy's Almagest in the 10th century.