"Of course, we have no early medieval Pompeii that would allow us to make a true and fair comparison of levels of casual secular literacy between Roman and post-Roman times. But we do have plenty of domestic objects from both periods, and these are a rich source of scratched letters and names in the Roman period, as well as of occasional messages (like those we have seen on tiles from Britain). In the early Middle Ages, domestic objects are almost always mute. They do very occasionally have names carved or scratched on them, but these are almost invariably very neat, suggesting that they have been applied with some care, perhaps even by a specialist writer, rather than roughly scratched by the owners themselves. There is no group of finds from post-Roman centuries that remotely compares with the 400 graffiti, mainly scratched initials, on the bottoms of pots from a Roman fort in Germany, which were almost certainly added by the soldiers themselves, in order to identify their individual vessels.
"In a much simpler world, the urgent need to read and write declined, and with it went the social pressure on the secular elite to be literate. Widespread literacy in the post-Roman West definitely became confined to the clergy. A detailed analysis of almost 1,000 subscribers to charters from eighth-century Italy has shown that just under a third of witnesses were able to sign their own names, the remainder making only a mark (identified as theirs by the charter's scribe). But the large majority of those who signed (71 per cent) were clergy. Amongst the 633 lay subscribers, only 93, or 14 per cent, wrote their own name. Since witnesses to charters were generally drawn from the ranks of the 'important' people of local society, and since the ability to write one's name does not require a profound grasp of literary skills, this figure suggests that even basic literacy was a very rare phenomenon amongst the laity as a whole" (Ward-Perkins, The Fall of Rome and the End of Civilization  166).