It may be worth noting that working-class characters in Shakspere could frequently read & write: think of the banausic actors in Midsummer Night's Dream, all of whom were given their parts written out by Peter Quince, and could read them; or the passage in Much Ado where Dogberry the constable asks the watch which of them would be best fitted to be his deputy, and receives the answer "Hugh Oatcake, sir, or George Seacole, for they can write and read": which it seems to me implies that these were abilities respected and striven for among ordinary working people in the early C17 .