An idea that I’ve been meaning to track down for a while is a vaguely remembered story about an official being required to recite the entirety of the law. There are several stories of someone being required to recite the entirety of some body of law, but the relevant one appears to be the Scandinavian office of lawspeaker.
Allowing for the fact that the official’s recital was done in thirds in succeeding years, assuming that he could hold an audience – not to mention his voice – at 150wpm, 8 hours a day for, say, 3 days per year this gives 648 000 words or about 1 300 pages of text.
A society whose entire law could be expressed in 1 300 pages of text would have limited use for lawyers.