διαφορὰν καὶ προτροπήν. The irony here is so obvious as to make the proposed reading (διαφθορὰν καὶ παρατροπήν, corruption and depravation) unnecessary. Otto prefers the reading adopted above. Trollope, on the other hand, inclines to the latter reading, mainly on the score of the former expressions being unusual. See his very sensible note in loc.