What plan does Granger have for keeping the information of books and then getting it back to mainstream society?

From the text:

We'll pass the books on to our children, by word of mouth, and let our children wait, in turn, on the other people. A lot will be lost that way, of course. But you can't make people listen. They have to come round in their own time, wondering what
happened and why the world blew up under them. It can't last."