Why write books?

[Mintos]

I do not quite understand that yet. So I bought a book for let's say mills.
My Lord learned it. And then wrote a book about it. Now I have 2 of the same book. What is the use case for this? To sell the second book?
I thought the Library exists so that when I buy -> learn -> write books, the knowledge remains permanent, even after the death of the lord. Unless someone burns down my library of course.
So yeah, still not 100% what's the use case for more books of the same title is and what an easy way is to keep knowledge even after a lords death.
I guess it's also a bad idea to have all the knowledge on one lord as if they die I'm pretty f'd, right?

[Osttruppen]

yes, the only use case for writing a book is to sell it. The more advanced the knowledge, the more you sell for. You can also let the lord with all the knowledge educate other lords to preserve their knowledge.

[ZoNeSRuS]

The game has a concept like "deep conversation" (I don't know how to speak English correctly). The essence of it is that you can send your lords to exchange experience in other cities. And in order not to lose knowledge after the death of the lord, it must be written down in a book.

[GreyHounD]

Books are your kingdom's wisedom. To use one books knowledge, at least one of your lords/ladies must have read that one. Otherwise that knowledge is lost, e.g. you can no longer building (and/or use) something. So placing all your knowledge on one person could be risky, yes. Check it out, sometimes you can make a pretty penny by creating additional books and selling those. Keep one, sell the rest so to say.

[bwc153]

Bandits can steal your books, so having spares doesn't hurt. I sell my extras though.

It's also possible for your lords to learn knowledge (inspiration or wise chat) and not have a book, so it's also worth writing the book in that circumstance. It seems like inspirations are more likely to happen for techs related to lords' inspections. IE: Logging knowledge if inspecting logging huts

[Gedsaro]

In terms of selling, i dont think level 1 books are worth doing, takes 6 hours with a decent Int lord, but you dont get much more money from selling it than you would get from just selling the 3 paper you used to write it, and id you vought the paper to write the book you likely dont even make your money back.
Level 2 books however, take the same amount of paper, maybe 3 more hours to write, and sells for 2x as much, so you should.make around 50-75 $ depending on trade skill.

Havent done lwvel 3 books yet, but id image they take 2x as long to write but will pay 3x better than level 1.

[Keeper_83]

Some Lords also like to write books and regularly get a demand for this activity.

[Fashbinder]

at the start of the game im poor, i learn the books then sell them. Near end game im rich, so i can rebuy or rewrite. I had a pawn with a desire to write a book twice.