An Imprimatur is an official declaration from the hierarchy of the Roman Catholic Church that a literary or similar work is free from error in matters of Roman Catholic doctrine and morals, and hence acceptable reading for faithful Roman Catholics. Ordinarily an imprimatur is granted by the bishop of a diocese (after a declaration of nihil obstat has been granted by a theologian in regard to the work). On rare occasions, a bishop's imprimatur may be overruled by higher authorities within the Catholic Church; this happened twice in 1984 and again in 1998.
It is of greatest significance in works directly addressing Roman Catholic theology and doctrine, and was introduced as a measure to reduce exposure, particularly of the laity, to heresy. The presence of the imprimatur was at one time a matter of the greatest concern to many Roman Catholics. (In fact, in some officially Roman Catholic countries, nothing could be legally published without such an imprimatur. This was a form of prior restraint or censorship.) Today it is likely of concern only to more orthodox Roman Catholics; however, it is also required under canon law that all religion textbooks in Catholic schools must have received the imprimatur.
A Roman Catholic imprimatur could formerly require up to four steps:
- Nihil obstat (Latin, meaning "nothing hinders") — This indicates that the work has been examined and approved by a delegated censor and that he finds it free of doctrinal or moral error. The censor is often a scholarly priest, and it is his task to work back-and-forth with the author of the work to correct any inaccuracies or problems. For works produced by members of religious orders, two nihil obstats from members of the order were formerly necessary.
- Imprimi potest (Latin, meaning "it can be printed") — If the work was that of a member of a religious order, this indicated that it had first been examined and approved by the religious superior or head of the religious order (or a duly appointed representative). This was given only after the two nihil obstats had been obtained from censors delegated by the superior of the religious order.
- A nihil obstat from the censor of the diocese in which publication takes place was, and still is, always necessary to obtain the imprimatur itself. The censor in this case is appointed by the bishop, and may be a priest given general authority for this or assigned specifically for an individual book (allowing the bishop to choose a scholar most qualified in a given field to examine the work). Even if the above nihil obstats had been obtained, and the imprimi potest, this diocesan nihil obstat was also always necessary. Today, most books need just this nihil obstat.
- Imprimatur (Latin, meaning "let it be printed") — This is the actual final approval by the bishop of the diocese where the work is to be published, or by other ecclesiastical authority. It is given under the bishop's role as chief teacher of the faith within his diocese.
Following this, some works may also include the following statement:
"The Nihil Obstat and Imprimatur are official declarations that a book or pamphlet is free of doctrinal or moral error. No implication is contained therein that those who have granted the Nihil Obstat and the Imprimatur agree with the content, opinions or statements expressed."
While at first glance this statement might seem contradictory, it indicates the purpose of the imprimatur: theologians and other writers are free to discuss various theories, ideas, approaches, or positions on theological topics - even if the bishop does not agree with the author's positions - provided they do not actually harm Catholic faith or morals. Within Catholic doctrine, therefore, a breadth of possible opinions may be freely discussed.
Imprimaturs are not automatically transferrable to later versions of a work. Any new edition also requires a new imprimatur to be obtained.
The imprimatur can be revoked if, upon further examination, any doctrinal or moral error is found to be contained in the work.