Public availability of text

The advent of woodblock printing in China (c 700 AD) and the widespread use of the printing press in Europe (c 1450 AD) meant that books and texts now became available to a much wider public. By using technology rather than error-prone human transcription, authors were able to exert more control over the precise contents of texts. It was now possible for two readers at different ends of a country to pick up copies of the same edition, and see exactly the same sequence of words. This is obviously useful for experiment (as well as for espionage - you can just send the word numbers from an agreed edition of some code-book, and those not in on the joke will be unable to decode the message unless they guess which book is being used)