4 Now let the proud and swelling necks of the heretics raise themselves, if they dare, against the holy humility of this address. You mad Donatists, whom we desire earnestly to return to the peace and unity of the holy Church, that you may receive health therein, what have ye to say in answer to this? You are wont, indeed, to bring up against us the letters of Cyprian, his opinion, his Council; why do ye claim the authority of Cyprian for your schism, and reject his example when it makes for the peace of the Church?
But who can fail to be aware that the sacred canon of Scripture, both of the Old and New Testament, is confined within its own limits, and that it stands so absolutely in a superior position to all later letters of the bishops, that about it we can hold no manner of doubt or disputation whether what is confessedly contained in it is right and true; but that all the letters of bishops which have been written, or are being written, since the closing of the canon, are liable to be refuted if there be anything contained in them which strays from the truth, either by the discourse of some one who happens to be wiser in the matter than themselves, or by the weightier authority and more learned experience of other bishops, by the authority of Councils; and further, that the Councils themselves, which are held in the several districts and provinces, must yield, beyond all possibility of doubt, to the authority of plenary Councils which are formed for the whole Christian world; and that even of the plenary Councils, the earlier are often corrected by those which follow them, when, by some actual experiment, things are brought to light which were before concealed, and that is known which previously lay hid, and this without any whirlwind of sacrilegious pride, without any puffing of the neck through arrogance, without any strife of envious hatred, simply with holy humility, catholic peace, and Christian charity?
Source: On Baptism, Against the Donatists (New Advent)