Church restrictions on dating and marriage
In accord with canon 108.3, we count the persons in both lines, but not the common ancestor(s).There are only two people involved here, and therefore Nancy and Mark’s relationship is considered second-degree consanguinity in the collateral line. Obviously not, because canon 1091.2 states that marriage in the collateral line is invalid up to the fourth degree, and their relationship is much closer than that. Let’s say that Susan’s mother Mary is the sister of Uncle Bill.
And unfortunately, there’s one more added twist to complicate things even further.First cousins, therefore, cannot marry in the Church.As for second, third, and other cousins, however, their degree of consanguinity is farther removed—they are related in the fifth, sixth, and even further degrees of the collateral line. I don’t want to marry my cousin, I’m just wondering!–Jeremy A: When it comes to the biological relationship between prospective spouses, the Church has laws which are based on natural law.