 A famous casuist, he was a consultor of the Holy Office of the Kingdom of Sicily and an examiner of bishops under Urban VIII, Innocent X, and Alexander VII.Harshly attacked in Blaise Pascal's "Provincial Letters", notably for his famous legitimation of duels, Diana himself claimed that as a rule his solutions followed the milder opinion.On the frontispiece of his "Resolutiones Morales" round a figure of the Cross runs the legend "Non ferro sed ligno".