 It recorded the instances where slavery was sanctioned by Councils and Popes and also censures and prohibitions that have been recorded throughout the history of the Church.He explains that what appears to the layman, not familiar with the intricacies of Church teaching and law, to be contradictory teaching, often involving the same Pope, is actually only a reflection of the common and longstanding concept of permissible "just slavery", and "unjust slavery" which was subject to condemnation.He shows by numerous examples from Council and Papal documents that “just slavery” was always an acceptable part of Catholic teaching right up until the end of the 19th century when the first steps were taken to place all forms of slavery under the ban.