Q - A "nihil obstat" and an "imprimatur" appear at the front of many Catholic books. What exactly do these mean?
A - Thanks for the question. When a Catholic writer has a book on faith, morals, theology, etc. they submit it to the Bishop in their diocese or the Bishop of the diocese of the publisher of the book. The Bishop, or his appointed representative, then reads through the book and either gives or denies a "nihil obstat" to it.
This approval comes in two official steps:
- "nihil obstat" means nothing "stands in the way" of it being printed - that is, nothing contrary to the faith and morals of the Church is in the book.
- "imprimatur" is the official permission to print the book.
The Code of Canon Law discusses this issue in Canons 822-832.
I hope this helps.