To make the information found in Mr. Hubbard’s books available for study at home, churches of Scientology provide extension courses on many Dianetics and Scientology books. Each extension course covers one of Mr. Hubbard’s books in full and is designed to give the reader a complete understanding of the subject matter.
Lesson books are provided with the extension courses. The reader completes the corresponding lesson as he reads the book and then mails it to his local Scientology church or mission. There, a church staff member reviews the lesson, sends a reply and helps with any difficulties. Extension courses help to deepen one’s understanding of Dianetics and Scientology books and are an excellent way to acquire such knowledge.