Weylan Deaver quotes Alexander Campbell telling this story about his father:
“In my boyhood, when entering into his study, in which he had a large and well-assorted library, I was wont to wonder on seeing, with a very few exceptions, only his Bible and Concordance on the table, with a simple outfit of pen, ink, and paper. Whether he had read all these volumes, and cared nothing more for them, or whether he regarded them as wholly useless, I presumed not to inquire, and dared not to decide. But such was the fact” (Memoirs of Elder Thomas Campbell, p. 271). via Of Making Many Books.
Check out the whole article, very worth your read.