Ad Beatissimi Apostolorum §23

²³ As regards matters in which without harm to faith or discipline - in the absence of any authoritative intervention of the Apostolic See - there is room for divergent opinions, it is clearly the right of everyone to express and defend his own opinion. But in such discussions no expressions should be used which might constitute serious breaches of charity; let each one freely defend his own opinion, but let it be done with due moderation, so that no one should consider himself entitled to affix on those who merely do not agree with his ideas the stigma of disloyalty to faith or to discipline.