A special exercise of the Divine power upon the writers of the books of the Bible in virtue of which God Himself is the principal author of these books and man is the subordinate author.
Though God used man as His instrument in writing these books, He did so in harmony with man's nature, no violence being done to the natural activity of his human faculties.
The classical explanation of how God inspired the sacred writers is contained in Pope Leo XIII's Encyclical "" ():
"For by supernatural power God so moved and impelled them to write, He was so present to them, that the things which He ordered and those only they first rightly understood, then willed faithfully to write down, and finally expressed in apt words and with infallible truth."
This explanation distinguishes four chief elements in inspiration:
All this may take place with such naturalness and gentleness that the author may not be conscious of being inspired just as in the performance of an ordinary act of virtue a good man may give no thought to whether he is swayed by natural or supernatural influences; but it is generally held that most of the sacred writers were aware that they were inspired.
Inspiration does not necessarily involve revelation of the matter to be written; still it does not exclude such revelation; many of the sacred writers already knew the matter to be written or were able to learn it by natural means.
Saint Luke in his preface speaks of the care he had used in investigating his subject.
- the things written were those and those only which God ordered to be written, hence God determined the matter to be presented
- the intellect of the human writer was illuminated by supernatural light so that he understood these things as matter to be written down
- his will was moved by the divine influence so that he resolved to write these things faithfully
- in the act of writing he was assisted by God so that he selected words fitted to express these things with infallible truth
Inspiration extends to everything written down originally by the human author; during his entire writing he was under the influence of inspiration and so everything he wrote was inspired and stands now as the written word of God revealed to all who read it.
If later on others made mistakes or changes in copying his book, these would not be his work and hence would be uninspired.
All error is excluded from the Bible since God is its principal Author; if it contained error, God Himself would be responsible for that error, but this is impossible because of His infinite knowledge and truthfulness.
Hence everything in the original books is infallibly true in the sense intended by the author.
Historical events must be supposed to be narrated as they actually occurred, but poetical books or passages are to be judged according to the rules of poetry where the imagination is given freer play; phenomena in physical nature may be described in the way they strike the senses and not in the strictly scientific manner.
Scholars differ regarding the nature and necessity of "verbal inspiration."
In its older form of exterior dictation it is practically abandoned, but the controversy continues between those who contend that in some way the words to be written must be suggested to the author by God and those who hold that, once the ideas have been inspired, the writer needs only guidance in selecting fit words from his vocabulary.
New Catholic Dictionary