_Causes of the Apostasy.--Internal Causes_.
Diverse effect of persecution.--Imprudent zeal of some.--Return to
idolatry by others.--"Libels" attesting individual apostasy.--Sad
condition of the Church in third century.--Testimony as to
conditions of apostasy at this period.--Decline of the Church
antedates the conversion of Constantine.--Departure from
Christianity.--Specific causes of the growing apostasy.