St. Gregory the Great
Dialogues
The Fourth Book › Chapter Twenty-eight: That, As We Believe the Souls of Just and Perfect Men to Be in Heaven; So We Ought Also to Believe That the Souls of the Wicked, After Their Departure From the Body, Be in Hell.
Chapter Twenty-eight: that, as we believe the souls of just and perfect men to be in heaven; so we ought also to believe that the souls of the wicked, after their departure from the body, be in hell.
GREGORY. If, by the testimony of holy scripture, you believe that the souls of holy and perfect men be in heaven: by the same reason ought you also to believe that the souls of the wicked be in hell: for as just men do rejoice and be glad at the retribution qf eternal justice, so necessary it is that the wicked at the same justice should be grieved and tormented: for as heavenly felicity doth glad the elect, so we ought to believe that, from the day of their departure, fire doth afflict and burn the reprobate.
PETER. With what reason can we believe, that corporal fire can hold and torment an incorporal thing?
Source: Dialogues (Tertullian.org)