The world was changing. Christianity was coming to the fore, presenting what to pagan philosophers seemed like new and impious doctrines. Porphyry, an older contemporary of Iamblichus, wrote a detailed attack of the new religion. Christian religious authorities deemed it so dangerous that it was publicly burned in later years and exists now only in fragments.
John F. Finamore, Professor and Chair, Department of Classics, University of Iowa, President of the U.S. Section of the International Society of Neoplatonic Studies.