The reason why vernacular literature eventually became the preferred way to produce books is because the "vernacular" was something that the majority of people could understand in terms of written language--meaning that a publisher and writer would make much more money printing in this language.
The candidate had to be trained as a scholar and then pass a series of written examinations. The Chinese civil service system, established in 124 B.C.E., required potential officials to be trained as scholars and then pass rigorous examinations to qualify for office.
