IV. The Nicene Canons are for universal application and not to be wrested to private interpretations.
These holy and venerable fathers who in the city of Nicæa, after condemning the blasphemous Arius with his impiety, laid down a code of canons for the Church to last till the end of the world, survive not only with us but with the whole of mankind in their constitutions; and, if anywhere men venture upon what is contrary to their decrees, it is ipso facto null and void; so that what is universally laid down for our perpetual advantage can never be modified by any change, nor can the things which were destined for the common good be perverted to private interests; and thus so long as the limits remain, which the Fathers fixed, no one may invade another's right but each must exercise himself within the proper and lawful bounds, to the extent of his power, in the breadth of love; of which the bishop of Constantinople may reap the fruits richly enough, if he rather relies on the virtue of humility than is puffed up with the spirit of self-seeking.
Source: Letters (New Advent)