13 For we see with deep sorrow what Our predecessor of immortal memory, Leo XIII, lamented: "Lies are boldly insinuated... into weighty tomes and slender volumes, into the transient pages of periodicals and the extravagant advertisements of the theater."(7) We see "books and magazines written to mock virtue and exalt depravity."(8)
Source: Ad Petri Cathedram (Vatican.va)