From the Council of Vannes, about A.D. 465

Canon II. We establish that those who, having left their wives, as is said in the Gospel, except for the cause of fornication, without proof of adultery, have married others, are to be kept from communion.

These Fathers seem not to have been about to punish men of this sort who had married another if the adultery of the wife were proved. But consider that the canon is penal, by which a penalty is established for a crime. But since to marry another after an innocent woman has been dismissed is a special sin, there certainly could have been a reason why this sin would be specially struck, without its being lawful to infer from this that the Fathers would not otherwise disapprove those second nuptials.

Canon IV. Those who, having professed virginity and having obtained blessing through the imposition of hands (see the rite of imposition of the hand in the blessing of a professed virgin, no otherwise than for Greek deaconesses) under attestation of this purpose, have been detected in adultery (that is, their commingling with anyone at all is called adultery, as we have already heard from others), we judge are to be kept from communion with their adulterers.

Cf. Canon VI of the preceding Council of Tours.