One of the functions of the Congregation was to expurgate books, taking out the offensive passages.

A separate _Index expurgatorius_, pointing out the passages to be deleted or corrected was {423} published, and this name has sometimes incorrectly been applied to the Index of prohibited books.
[Sidenote: Effect of the censorship] The effect of the censorship of the press has been variously estimated.
The Index was early dubbed _sica destricta in omnes scriptores_ and Sarpi called it "the finest secret ever discovered for applying religion to the purpose of making men idiotic." Milton thundered against the censorship in England as "the greatest discouragement and affront that can be offered to learning and learned men." The evil of the system of Rome was, in his opinion, double, for, as he wrote in his immortal _Areopagitica_, "The Council of Trent and the Spanish Inquisition engendering together brought forth and perfected those catalogues and expurging indexes that rake through the entrails of many an old good author with a violation worse than any that could be offered to his tomb." When we remember that the greatest works of literature, such as the _Divine Comedy_, were tampered with, and that, in the Spanish Expurgatorial Index of 1640 the list of passages to be deleted or to be altered in Erasmus's works takes 59 double-columned, closely printed folio pages, we can easily see the point of Milton's indignant protest.

But, to his mind, it was still worse to subject a book to the examination of unfit men before it could secure its _imprimatur_.

Not without reason has liberty of the press been made one of the cornerstones of the temple of freedom.
Various writers have labored to demonstrate the blighting effect that the censorship was supposed to have on literature.

But it is surprising how few examples they can bring.