"Attributing a book to a famous early source added not only to-the authority of the book, but also to its market price in what was evidently a flourishing book bazaar in Baghdad. That many books were fakes and falsely attributed to famous early sources is evident from the Eihrist of al Nadim, a Baghdad shopkeeper of the 10th c., who hence prepared this fihrist or list of books he regarded as genuine. Of course, al Nadim was a shopkeeper, not a scholar, and his concerns about genuineness were limited to saleability—so, common hearsay was good enough for him— and he is unlikely to have been bothered by a well-established fake."